Ignition Solutions for Small Engines and Garden Pulling Tractors

Please check out: HOT ROD GARDEN TRACTOR PULLERS ASSOCIATION, Miller's Pulling Sled Rental and A-1 Miller's Performance Enterprises - Online Catalog

General information - Updated 5/22/14. (Click Refresh to see changes or updates.) Optimized for 1024 x 768 screen resolution. To search for a word or phrase in any of my web sites, with Microsoft Internet Explorer 6.x, or Google Chrome, press CTRL+F to open the Find dialog box. Or scroll down, or jump to...


Safety First! Fabricating a Killswitch -

Killswitch ComponentsTo fabricate a killswitch circuit for a battery-ignition garden tractor, use a heavy-duty electrical (120v) 3-prong plug and a matching 3-prong receptacle, like the ones shown to the right. About 4' of 14 gauge 2-wire double-insulated electrical wire will also be needed. Although ordinary lightweight "lamp cord" will work, double-insulated wire would be more durable to prevent a short. Connect the wires so the ignition and electric fuel pump circuits will be disabled when the plug is pulled from the receptacle.

Here's how to connect the wires:

  1. Simple Diagram of the Killswitch CircuitInside the plug, connect the two flat terminals together with a short wire. Don't run any wires outside of it.
  2. Securely fasten a steel loop on the end of the plug. (A key ring works perfect.)
  3. On one of the [flat] terminals in the receptacle, connect the wire that comes from the ignition switch (positive side of the battery).
  4. On the other [flat] terminal in the receptacle, connect another wire that goes to the ignition system and electric fuel pump.
  5. Do not use the grounding terminal on the receptacle or plug. It's only purpose (as a killswitch) is to secure the plug in the receptacle and keep it from falling out when pulling.
  6. Fabricate a bracket to mount the receptacle on the rear of the tractor, just above the hitch.
  7. Route the wire in a safe manner so it will not get pinched or make contact with the ground or chassis of the tractor.
  8. Install the killswitch conveniently located just above to the pulling hitch within easy reach.

Or for a magneto/solid state ignition system or for a battery-powered ignition system, the "grounding" type of kill switch can be used. This is actually a breakaway safety/kill switch for an ATV, jet ski, boat or trailer. When used with magneto or solid state ignition, with the plunger pulled, it grounds the coil from producing spark. One wire is grounded to chassis ground and the other wire connects to the wire going to the points/condenser or the kill terminal on the coil w/integrated module or a remote module. But when used with battery ignition, with the plunger pulled, this type of switch do not disconnect power to the coil. Instead, it grounds the negative side of the coil. One wire is connected to chassis ground, and the other wire connects to the negative (-) terminal on the coil. (Connects to the same wire going to the points/condenser or crank trigger module.) When the plunger is pulled out (when pulling), the ignition switch should be immediately turned off to prevent power from continually going to the coil, which can eventually burn it up. On the down side, this type of switch do not disable power to the electric fuel pump on a pulling tractor. The electric fuel pump must be disabled manually by an OFF/ON switch. This breakaway safety switch can be purchased off of eBay for a reasonable price.


Ignition Solutions -

Spark-ignited engines require a spark to initiate burning of the air-fuel mixture in the combustion chamber. The spark in each cylinder is provided by a spark plug and is actually a flow of electrical current through the air and fuel vapor between the closely spaced electrodes of the spark plug. The resistance of air is very high. Therefore, a 15,000- to 30,000-volt potential across the gap is used to fire the plug. Typically, the ignition system must supply this high voltage from a 12 volt power source, such as a storage battery. Moreover, the spark must begin at the proper point in the cycle and must be of sufficient duration.

Whenever a manufacturer wants to sell their latest fancy ignition system, they run a bench test that shows that their unit puts out more voltage than the other guy's. If you read enough ads with claims of extremely high available voltage, you may begin to think that voltage is the only thing necessary to make an ignition system the best in the world. After all, if ignition "A" puts out more voltage than ignition "B", the one you would want is "A", right? Sorry, but that isn't necessarily so. Ignition "A" may put out more voltage, but is it more mechanically dependable than ignition "B"? Did you know that 90% of ignition failures are mechanical, and not electrical? Blame burnt or dirty points, faulty condenser, bad switch(es), broken or chaffed wires, loose screws or connectors, slipped timing, worn hinge pin hole in points, etc. Apply oil or grease on the hinge pin before installing points so the hole will last longer. When it's dry, it'll wear prematurely, effecting ignition timing, resulting in loss of engine power. By the way - whenever a condenser goes bad, the engine will either: 1. Not start. 2. Start and idle fine, but when the speed increases, it'll either not accelerate or run very erratic. IMPORTANT: Always install condensers with the wire or terminal facing down so rain water and/or when washing off engine, water will not enter into condenser, ruining it.

The importance of extremely high secondary voltage for more performance has been somewhat overplayed. An ignition system, regardless of type, produces only enough voltage necessary to jump the spark plug gap and ignite the air/fuel mixture. In perfect condition, a good spark plug wire and spark plug with a gap of .035" can't handle much more than 32,000 volts. If an ignition could produce more than that, then the extra voltage would escape through a leaking spark plug wire, a small crack in the coil tower, etc. Besides, an average engine simply just doesn't need that much voltage. In most cases, an average engine simply don't need a high-output/performance (40,000 volt) ignition coil. If a plug requires only 10,000 volts to jump its gap, then a "Super Coil" that's advertised to produce 40,000 volts will produce just 10,000 volts for that same plug under the same conditions. A coil advertised to produce 40,000 volts may have the potential to do it, but unless everything is in excellent condition, only a fraction of that voltage would reach the spark plug.

As a spark plug's electrodes wear, its gap increases, so more voltage is required from the ignition coil before the spark is able to jump across the gap. If uncorrected, the gap eventually increases to the point where the plug requires more voltage than the coil can produce. However, a high-output/performance ignition coil would probably be able to fire the worn plug. Did you know that most stock ignition coils will produce enough voltage to jump a gap of up to 3/4 of an inch? Of course, no spark plug electrode will ever wear that wide. Therefore, the use of a high-output/performance ignition coil really isn't necessary, except in extreme high compression, alcohol-burning engines.

In most cases, if an engine is kept in perfect tune, the factory stock ignition system provides more than enough voltage for the average garden pulling tractor. Most conventional stock ignitions are designed to provide a hot spark up to a relatively low engine speed. With Kohler engines running in modified form, they will get up as high as 9,000 rpm. But at high rpms or at wide open throttle with the points system, the points open and close so quickly that the coil's primary winding has less time to absorb voltage. This means the condenser doesn't have enough time to rebuild the capacitance discharge. As a result, with the stock system, secondary voltage to the plug decreases and the engine won't run at its full potential or it may sputter just when victory is in sight. However, for most garden pulling tractors, a stock ignition system that's in good condition will provide plenty of spark. IMPORTANT: Always install condensers with the wire or terminal facing down so rain water and/or when washing off engine, water will not enter into condenser, ruining it.


There are 5 types of ignition systems that's used on all small gas engines, despite if it's a 2- or 4-cycle engine:

  1. Magneto Ignition is a mechanical ignition system. It has breaker points, a condenser and an ignition coil that generates it's own electrical power to produce the spark every time a magnet in the flywheel or rotor passes the coil. Magneto ignition coils can't be used for a battery ignition system because they must generate their own electrical power to create the spark. The ignition timing for the magneto ignition is the same as for the battery ignition. It's set or adjusted by widening or narrowing the gap of the breaker points. This advances or retards the ignition timing. Use a test light with battery power or an analog multimeter set on the ohms (d) resistance (with the engine not running) or an inductive or non-inductive automotive strobe timing light (with the engine running) to set the ignition timing on a magneto system, but a 12 volt battery must be available to power the timing light. Because of their compactness and no need for an outside power source, magneto ignition is very popular on virtually all small engine equipment. Such as gas-powered string trimmers, chainsaws, lawn mowers, garden tillers, go-karts, riding mowers, lawn tractors, lawn & garden tractor and small construction equipment engines. How magneto coils produce a spark.
    • Most cast iron block and certain [bigger] aluminum block air-cooled small gas engines having an obsolete magneto ignition system with points and condenser can be easily converted to battery ignition. All that's required is a condenser that's designed for battery ignition (automotive or Kohler), a 12 volt automotive-type ignition coil with a bracket, a ballast resistor if the coil requires one, a spark plug wire with terminals and boots, a 12 volt battery and wiring/connectors. The same ignition points and spark plug can be used. Due to the more powerful automotive coil, the spark plug gap can be set at .035" for a hotter spark. Also, the key-operated [magneto] ignition/starter switch will need to be changed to an automotive-type switch that's designed for battery ignition. Or, an OFF/ON push/pull or toggle switch to power the ignition and a push-button switch to activate the solenoid/starter motor can be used instead. And with battery ignition, the engine will need a reliable charging system to keep the battery fully charged to crank the engine and so the ignition will produce a hot spark. When converting to battery ignition, remove or disconnect the magneto coil and condenser first. Please go here if you need a kit to convert an engine to the battery ignition system.
    • The reason battery ignition can't be used on the smaller aluminum block Briggs & Stratton engines is because the [B&S] condenser is part of the ignition points. For battery ignition to work, the wire on the [battery] condenser must be connected to the negative (-) post on the [battery] ignition coil, and the body of the condenser must be grounded to the engine. Therefore, if the condenser is separate from the points, it should work. For a hot and reliable spark on the smaller aluminum block Briggs & Stratton engines with the condenser as part of the points, install a Briggs & Stratton's Magnetron™ Solid State ModuleB&S's Magnetron™ electronic ignition module (only for two-post coils), a NOVA 2 solid state module or a Mega-Fire solid state module (for two or three-post coils). Please contact me if you need a NOVA 2 or Mega-Fire solid state module.
      • NOTE: Sometimes the Magnetron™ module requires that the magnets in the flywheel be re-polarized by Briggs & Stratton to get a spark. But the NOVA 2 or Mega-Fire modules doesn't require that the flywheel magnets be re-polarized. If a spark doesn't occur with the two wires connected to either module, just simply reverse them and then it should spark. Magnetron™ doesn't work this way.
      • On engines with a magneto ignition, I believe the best thing to do is install one a NOVA 2 or Mega-Fire module and your ignition problems should be no more. Because sometimes I too, have a hard time with points and condenser trying to get a spark from certain Kohler engines with magneto ignition. Sometimes I have to set the points as close as .015" just to get a spark. But this makes the timing so retarded, the engine lacks power. So I remove the points and condenser, plug the points plunger hole, and install a NOVA 2 module. The engine then has a strong spark, starts quicker and produces a lot more power. The module puts the timing right where it needs to be. I always get a good spark with battery ignition. But magneto ignition with points and condenser can sometimes be difficult to get a spark and get the timing set right. I think it's due to a worn points lobe on the camshaft.
  2. Battery Ignition is also a mechanical system. It uses breaker points, and a different type of condenser than magneto ignition, and an ignition coil that requires a 12 volt source (battery) to power the system. Battery ignition is used on most all older garden tractors, farm tractors and virtually all older (pre-1974) automobiles.
  3. Transistorized Breaker Point Ignition System is an analog ignition system. It provides a hot spark, allows the ignition points to last longer, perhaps the life of the engine, and it requires no condenser. It requires a 12 volt source (battery) to power the system. Ford Motor Co. originally offered the transistorized breaker point ignition system on various Ford vehicles from 1965 to 1972. The PointSaver™ transistorized breaker point ignition unit, available from Kirk Engines, Inc. (http://www.kirkengines.com) works great for general yard use and for pulling tractors. MSD also offers a transistorized breaker point ignition module to help points last longer. The "PointSlayer" from Overnight Solutions seems to be a good product and works somewhat like the crank trigger system. However, it uses an electronic sensor that detects movement of the points pushrod, like the transistorized breaker point ignition system. The PointSlayer kit comes with a custom pushrod and a spring that slips over it. The spring's job is to keep the rod against the cam's points lobe. The rod is stepped down, and the spring rides between the step down ledge and the back of the PointSlayer. The only drawback with this system is if the points lobe on the camshaft is worn or becomes worn overtime, the ignition timing will become retarded and cannot be advanced enough so the engine will run efficiently. Go here to construct your own transistorized point ignition module: Simple Transistorized Ignition Retrofit for Old Cars.pdf or Build_Your_Own_Electronic_Ignition.pdf. (Each link requires Adobe Acrobat Reader and use Google Chrome web browser for a faster download.) One thing to take into consideration about using a transistorized breaker point ignition system is if an engine sits for a long period of time, the point contacts may become oxidized because there's not enough "spark" or electrical current going between the contacts to burn away the oxidation. And being the transistorized breaker point ignition system requires activation of the ignition points, if the points lobe on the camshaft is worn or becomes worn, the ignition timing would be retarded.
  4. Breakerless or Solid State Ignition is a 100% digital system and requires no mechanical or physical contact to activate any moving parts. It operates on the same general principle as the magneto system but does not use breaker points to time the spark and a conventional condenser. Instead, a trigger module containing solid state electronics performs the same function as the breaker points. Because there are no breaker points in this system, there are no requirements for ignition timing (on a small engine). Like magneto ignition, solid state ignition is self-energizing. Therefore, it does not require an outside electrical source, such as a battery. Breakerless ignition is pretty much maintenance free, with very few parts to wear out or go bad. Breakerless or solid state ignition is used on virtually all small engines built from 1982.
  5. Crank Trigger [Electronic] Ignition is also a 100% digital system and requires no mechanical or physical contact to activate any moving parts. It's a combination of the breakerless and battery ignition because it has no breaker points or condenser but requires a 12 volt source (battery) to power the ignition coil and an electronic ignition control module. Virtually all large engines (farm tractors and automobiles) that's built from the mid-1970s use either crank trigger ignition, or a system similar to crank trigger.

By the way - it's best to use a quality-made automotive battery in a pulling tractor that have its own starter motor, but no charging system. Not only because an automotive battery holds a charge longer to crank even the toughest engine after several pulls, but they provide plenty of power to a battery-powered ignition system for a hotter spark.


Information about Ignition Coils -

Certain standard-output/ordinary ignition coils and most high-output/performance ignition coils require an external ballast resistor (made for any 1955-57 General Motors vehicle) or a full-length resistance ignition wire (out of any 1958-74 GM vehicle) to prevent putting too much voltage through the primary circuit in the coil, which could burn up the coil and points. A ballast resistor or resistance wire is basically a voltage reducer that reduces 12 volts down to anywhere between 6-9 volts, depending on the load. (The ballast resistor shown below Ê is the same used on the 1955-57 GM vehicles.) But if a coil reads "12 VOLTS" on its casing, then it has a built-in resistor. A resistor may not be needed with many new coils because most of them nowadays have a built-in resistor. And using a resistor effects the voltage output of a coil very little. It only prevents from burning it up, and it saves wear on the ignition points. The reason manufacturers don't install a resistor inside some high-output/performance ignition coils is because these coils draw more amps from the battery. This causes the resistor to operate at a higher temperature, which could overheat and damage the windings within the coil. If a high-output/performance ignition coil is preferred, when purchasing one, be sure to ask the salesperson if it has a built-in resistor or if it requires an external resistor. This is important for the life of the coil and ignition point contacts. The absence of the resistor will, without a doubt, increase voltage to the spark plugs, but could reduce the points life in breaker-points ignition systems. And a high-output/performance ignition coil has no effect whatsoever with crank trigger ignition when using a Chrysler or Ford electronic ignition control module. Also, most stock coils produce more than enough volts for even the hottest high performance engines built, especially when used with the crank trigger ignition.

Any ignition coil without a built-in resistor is a 6 volt coil, and can be safely operated with a 6 volt electrical system without a ballast resistor or resistance wire. But to use a 6 volt coil with a 12 volt electrical system, simply use a minimum 1.3 ohm ballast resistor in series to reduce the voltage to the coil. The coil should produce a hot spark, operate cool to the touch and last a long time. The points should last a long time, too.

Testing for Spark -

First of all, use a fully charged 12 volt battery and not an automotive portable battery charger alone to test for spark. Because most battery chargers produce 2-3 volts, enough power to charge up each cell at a time in a multiple cell (automotive) battery until it's fully charged. (The slow or low rate of charge prevents from overcharging the battery, possibly causing the acid to burn up or deteriorate, and it helps the battery last longer.) With that said, a simple way to test for spark with battery ignition, having points and condenser, is to connect a jumper wire from the positive terminal on the coil to the positive post on the battery, then either crank the engine, or with the points in the closed position, open and close them manually and with the spark plug grounded on a metal part of the engine or equipment, observe for an audible snappy, blue spark at the spark plug's tip. (The blue color is burning of hydrogen in the atmosphere, and the snap is the "sonic boom" or breaking of the sound barrier released from the rapid burning of the hydrogen.) If there's no spark, then either the spark plug is bad, the points are burnt or dirty, or the coil or condenser is bad. IMPORTANT: Always install condensers with the wire or terminal facing down so rain water and/or when washing off engine, water will not enter into condenser, ruining it. If there's a red or white spark, then the spark plug is bad. In rare cases, when cranking the engine and the points don't open and close, the points lobe on the camshaft may be severely worn.

How to Bench Test an Ignition Coil to Find if it Produces a Spark -

Although there are some fancy and high dollar coil testers available, the best (and cheapest) way I found to test a coil is on a work bench. Use jumper wires to connect the coil in a circuit with a new or known good condenser, a new or known good spark plug and a known good spark plug wire. Use a fully charged 12 volt battery. Common ground is [connected to] the negative post on the battery.

  1. Connect the positive (+) terminal on the coil to the positive (+) post on the battery.
  2. Connect the wire on the condenser to the negative (-) terminal on the coil.
  3. Connect the condenser body to common ground.
  4. Connect the spark plug body to common ground.
  5. Momentarily touch and remove the wire coming from the negative (-) terminal on the coil and condenser to common ground to simulate the opening and closing of the ignition points. The coil should produce a spark each time the wire is removed from common ground. See the drawings below Ê

Typical Battery (Points and Condenser) Ignition System for a Garden Tractor

If an ignition coil has a BUILT-IN resistor, connect the wires as shown below Ê...
NOT using a ballast resistor for the coil


But if a coil requires a ballast resistor, connect the wires as shown below Ê...
Using a ballast resistor for the coil

Testing the Strength of an Ignition System -

Universal Spark TesterWhen testing the strength of an ignition system, it can be tested at the spark plug's tip. Or better yet, it's best use a universal spark tester like the ones pictured to the right. But when testing the strength of the spark with the just the spark plug, always use a new spark plug, and the ignition must be strong enough to produce an audible "snappy" and visible bright blue spark at the plug's tip. A good spark plug is supposed to produce a blue, audible snapping sound with it placed somewhere on the engine when the engine is cranked. (The blue color is burning of the moisture content of the hydrogen in the atmosphere, and the snap sound is caused by breaking of the sound barrier.) If the spark is visibly white or red in color, either the [used] spark plug is fouled or the ignition coil is weak and needs replacing. Unlike gasoline, alcohol fuels (ethanol and methanol) will rarely foul spark plugs. And despite which gas is burned in a competition pulling engine, use only the type of spark plug that's recommended by the manufacturer of the engine. If the wrong type of plug is used, the engine will lose power.

Engines with a points/condenser magneto ignition system can be cranked over slowly to produce a spark. But most engines with a solid state ignition (B&S's Magnetron™) must be cranked over quickly to produce a spark. However, on engines with battery ignition, there's really no need to crank the engine to test for spark. What can be done is momentarily and lightly connect the point contacts with a small metal object, such as the tip of a screwdriver.

Also, if the spark plug's tip is black and/or has wet gas on it, and if you think the problem is in the carburetor, well, the carburetor is probably working fine because the engine is obviously getting plenty of gas. As an older, experienced mechanic once said, "Most carburetor problems are electrical." (Meaning faulty ignition system.) This has proven true more times than I can remember.

How to Test the Strength of an Ignition Coil's Output Voltage -

The way I test a stock coil is I connect it in a circuit, like it's on an engine and if it produces a spark with at least a 3/4" wide gap, it's a good coil. A high-output/performance ignition coil should produce a spark with a wider gap.

The differences between a point-ignition coil and an electronic ignition coilAll conventional point-type ignition systems that's installed on garden tractor and automotive engines utilizes a standard-output/ordinary [20,000-30,000 volt] coil. And all automotive electronic ignition systems utilize a high-output/performance (40,000 volt) coil. The differences in these coils is by the height of the center tower. The high-output/performance ignition coil has a taller tower, to keep the spark from shorting to the terminals. So if you want more spark, instead of using a high dollar, aftermarket high-output/performance ignition coil, you could just use a low-cost automotive one that's designed for an automobile with electronic ignition. (Early Chrysler and Ford products.)

On any ignition system, the voltage of the coil is the same at any rpm. The only way the coil will produce more voltage is when a solid wire spark plug wire is replaced with a suppression (carbon core) spark plug wire and/or a copper-core spark plug is replaced with a resistor spark plug, when the suppression spark plug wire and/or resistor spark plug gets weak (deteriorates with use), or if the gap on the spark plug is widened. The coil will produce less pulses of voltage at idle speeds and more pulses at higher rpm. But the amount of voltage will remain the same.

Ignition coil with two straps for better supportIf you've ever experienced the metal strap on an ignition coil of breaking due to normal engine vibration (especially at higher rpms or wide open throttle) and because the metal itself is too thin, then what you need to do is either fabricate a strap made of thicker metal, or install two coil straps as shown in the picture to the right, and be sure to fasten the straps securely. This will double the life of the clamps and lessen the chances of either strap of ever breaking again.

Ever had a good run going down the track and all of a sudden the engine dies, and then you found the cause was the ignition coil? Well, chances are, it wasn't designed for use on a garden pulling tractor, especially when the engine is ran at wide open throttle. Even new oil-filled canister coils have been known to fail in a very short time on a garden pulling tractor. The reason some coils fail is due to normal single cylinder engine vibration running at high rpms or wide open throttle. The tiny wires (or windings) inside the coil will vibrate and break over time. Even the insulation on the windings themselves will "rub" or scrape against the other internal wires, resulting in a short, and eventual coil failure. That's why it's best to use an epoxy-filled coil to prevent the windings from vibrating, shorting out and/or breaking. The epoxy holds the wires solid, resulting in no vibration of the windings whatsoever. Most epoxy-filled coils produce up to 45,000 volts, too. So for the little difference in price, accept no substitutes! Epoxy-filled coils are most reliable for use on a garden pulling tractor. Part numbers for popular epoxy-filled coils are: AC Delco part #'s U515, U501; ACCEL part # 8140HV; Bosch part # 00012; PerTronix part #'s 40111, 40611; Borg Warner part #'s BWD E40, E40P, E81; Standard part #'s UC15X, UF3 and MSD part #'s 8222, 8232. Some of these coils have an internal resistor and some require an external ballast resistor. To prevent prematurely burning the ignition points, it's best to test the coil with a digital multimeter to determine if it requires an external resistor or not.

How to Test the Ohms Resistance of a Ballast Resistor or Ignition Coil -

First of all, most ceramic-body ballast resistors do not have any indication (markings) of its ohms resistance. Therefore, it will need to be tested to verify the resistance for it to work correctly with the connected device. If it's used resistor, inspect the ceramic portion for signs of overheating. An overheated (overloaded) resistor will be dark or blackened. Such a resistor should not be used. And ignition coils have either an internal 1.5 or 3 ohm resistor, or no internal resistor. Most electronic ignition coils have no internal resistor. When in doubt if a coil have an internal resistor or not, or if you want to know the resistance of the resistor, it can be tested as follows:

  1. Tool needed: Digital multimeter (DMM, DVOM). This test cannot be performed accurately with an analog multimeter.
  2. Turn on the digital multimeter, plug the red test lead connector into the Vd receptacle, plug the black test lead connector into the COM receptacle, then select the 200 ohms (d) setting. On some multimeters, resistance is denoted by the capital Greek letter Omega (d), which stands for ohms. IMPORTANT: Make sure the digital multimeter is warmed to room temperature for an accurate reading.
  3. Connect the test leads together and observe the reading on the display. If it shows slightly higher than 0.0 of resistance, then this is the resistance in the test leads. It will need to be subtracted from the reading of the resistor or coil.
  4. With the ballast resistor or ignition coil not connected to anything, connect the test leads of the multimeter to the terminals on the ballast resistor or small terminals on the coil.
  5. The resistance will be displayed on the multimeter screen. It may take a few seconds for the multimeter to settle so it'll display the lowest resistance. If there's no resistor in a coil, the reading of the resistance in the lead wires will be displayed.
  6. Use a permanent felt tip marker (Sharpie) or paint marker (TEXPEN®) to write on the ballast resistor or coil of its ohms resistance or no resistor for future reference.

All automotive high-output/performance or OEM electronic ignition coils, including the popular Bosch blue coil, have more primary and secondary windings than a standard-output/ordinary coil. This is how they produce more voltage for a hotter spark. When used with a points/condenser ignition system, the energy of the primary windings within the coil is transferred into the condenser. And in most cases, one ordinary, standard capacity condenser isn't capable of handling the excessive amount of electricity from the primary windings to fully energize the secondary windings within the coil, thus allowing the coil to produce a low voltage or weak spark at any rpm, which will cause the engine to idle poorly and run poorly. Sometimes when using a high-output/performance ignition coil with one ordinary, standard capacity condenser, black smoke will blow out the exhaust at idle and flames will shoot out the exhaust at high rpms or at wide open throttle.

For a high-output/performance ignition coil to operate at 100% efficiency and produce full voltage at any rpm, it's best to use two ordinary, standard capacity condensers or one high capacity/performance condenser, such as an Accel condenser, part # 100108 (with the red wire and grommet), or Mallory condenser, part # 401 (gold color body and terminal). Two ordinary, standard capacity condensers doubles the capacity for the extra secondary windings within the coil. This will allow an engine to idle better, run smoother, and produce more power at high rpms or at wide open throttle. If an engine is built right, the ignition timing is set right, and if the carburetor is adjusted correctly, with a high-output/performance coil, two ordinary, standard capacity condensers or one high capacity/performance condenser, the exhaust (appearance) should be cleaner at idle, and with no flames at high rpms or at wide open throttle. A stock or standard-output/ordinary coil will not produce more voltage than what it is designed for with two condensers or a high capacity/performance condenser. But it will produce 100% voltage with two ordinary, standard capacity condensers or one high capacity/performance condenser. And with crank trigger ignition, if an electronic ignition control module with a high capacity transistor is used, a standard-output/ordinary or high-output/performance coil will produce 100% voltage regardless.

IMPORTANT: Always install condensers with the wire or terminal facing down so rain water and/or when washing off engine, water will not enter into condenser, ruining it/them.

When choosing a high-output/performance ignition coil, such as a Chrysler electronic ignition canister coil, if it reads on the casing: "use with electronic ignition" (or something like this), all this means is if the coil is used with full 12 volts, and with points and [one standard-output/ordinary] condenser, the points won't last long due to the high voltage going through them. To use the coil, simply install a [1.7 ohm resistance] ballast resistor before the coil to decrease the voltage going through the coil and the points, and the points should last longer. And definitely use two ordinary, standard capacity condensers or one high capacity/performance condenser so the coil will produce full voltage. IMPORTANT: Always install condensers with the wire or terminal facing down so rain water and/or when washing off engine, water will not enter into condenser, ruining it.

Causes of Engine "Popping" or Backfire -


How to Convert the Battery Ignition System to Solid State Ignition on Kohler Engines -

To convert the Kohler KT-series twin cylinder engines (KT17/KT17II, KT19/KT19 or KT21) to solid state ignition, the flywheel, left cylinder (when facing the flywheel), aluminum ignition coil mounting bracket and the solid state ignition coil off of a Kohler Magnum MV16, M18, MV18, M20 or MV20 engine will need to be used.

To convert the Kohler K-series single cylinder engines (K141, K160/K161, K181, K241, K301, K321 or K341) to solid state ignition, the flywheel, bearing plate, starter motor and solid state ignition coil off of a Kohler Magnum M8, M10, M12, M14 or M16 engine will need to be used. The M8 parts can be used on the K141, K160/K161 or K181 engines. And the M10, M12, M14 or M16 parts can be used on the K241, K301, K321 or K341 engines. The stator (under the flywheel) charging system will need to be used, too.

But if you choose not to use the Magnum engine components as mentioned above È, your only option is to keep using the ignition points and install the PointSaver™ from Kirk Engines, Inc. (http://www.kirkengines.com/). It eliminates the condenser and allows the points to possibly last the life of the engine.

When replacing the ignition coil on a model KT17, KT17II, KT19, KT19II or KT21 twin cylinder Kohler engines, instead of using the high-dollar OEM standard-output/ordinary Kohler coil, you can use two automotive-type canister coils with two condensers (one condenser per coil), a 2-post Harley-Davidson coil (this particular coil also fits Kohler engine models K482, K532, K582, K660/K662), or a GM DIS coil (Chevy 2 post coil; DIS stands for Distributorless Ignition Systems.) The DIS coil part numbers are AC Delco D555 or Standard Motor Products DR39X, and was used in select GM vehicles from 1985 to the 2005, one of which is the 2005 Chevrolet Impala. There's no certain way to connect the wires to the primary windings in the GM DIS coil. There is no positive (+) or negative (-) side. When using points with 12 volts, install a ballast resistor to prevent burning up the coil, and connect two ordinary, standard capacity condensers or one high capacity condenser so the oil will produce full voltage. A ballast resistor is not required with a 6 volt system. The DIS coil is a high-output/performance coil too, so the spark plug gaps can be set at .060" each, and it'll be a good thing to use two standard-output/ordinary battery ignition condensers so the coil will produce full voltage. IMPORTANT: Always install condensers with the wire or terminal facing down so rain water and/or when washing off engine, water will not enter into condenser, ruining it.

Go here to see how well the GM DIS coil works: Gravely 817 Onan CCKA Coil Replacement with Chevy GM DIS Coil - YouTube (Video posted by Ralph @ rw3dog@yahoo.com)

Causes of Ignition Coil Failures -

Most failures of battery ignition coils is caused by overcharging of electrical system due to faulty [automotive] battery or faulty voltage rectifier/regulator. Most battery ignition coils will last the life of an engine. But if a quality coil keeps going bad for no apparent reason, then there are three things that will cause a good coil to go bad. They are:

  1. Lack of a ballast resistor or a resistor wire before the coil. (If the coil requires one.)
  2. Bad or defective voltage regulator or rectifier. If the charging system continues to charge with no "falling back" reading on the amp gauge (overcharge), this will put too much voltage through the coil, eventually burning out the primary windings. Overcharging of the charging system could also burn up the electronic ignition control module (crank trigger), burn out light bulbs, electrical accessories and burn up a good battery.
  3. If a garden tractor is equipped with an automotive battery, it could have a dead cell or all the cells are weak. (Defective battery.) Unlike in an automobile, and if the starter motor is in good condition, a weak automotive battery will have more than enough cranking amps to crank over a small, single- or two-cylinder engine with no problem, and a drop in the battery's cranking amps wouldn't be that noticeable. Whether if it's in a garden tractor or an automobile, an automotive battery with a dead cell or weak cells will cause the charging system to continuously try to fully recharge the battery, but instead of the battery taking full charge, the charging system will put too much voltage through the coil for long periods of time, causing the windings within to burn up. If an engine has a battery-powered electronic ignition, this too, could burn up the electronic ignition control module, burn out light bulbs and electrical accessories. To determine if a battery is defective, use a load tester for sealed-top batteries, and for batteries with removable caps, test the battery's acid condition with a hydrometer battery tester (glass tube with floating balls [pocket size] or a floating bulb [full size]; which are available at virtually any auto parts store).
  4. Although rare, severe engine vibrations could cause the tiny wires inside the coil to break. Read more about this below Ê.

Why Do Some Magneto Ignition Coils To Go Bad?

Unfortunately, some coils don't last forever. As the spark plug's electrode deteriorates, the secondary windings within the coil is forced to produce more voltage to fire the plug. Eventually, the increase in voltage will burn out the windings, causing coil failure. This is why quality-made spark plugs should be used.

I think the Briggs & Stratton, Kohler KT-series and Magnum twin cylinder flathead engines are one of the best that was made. The only problem with them is these engines use one ignition coil to fire two spark plugs, one per cylinder, and after several years of use, sometimes the coil will fail to produce a spark, despite if the engine has points/condenser, Magnetron™ or a solid state module. This happens because one coil must fire two spark plugs at one time with the plug gaps set at .030" each (factory recommended setting). With these size gaps, this is the same as firing one spark plug with a gap of .060"! Most magneto coils are not designed to produce this much voltage and may not last a long. The coil is forced to produce more voltage than is necessary to fire both plugs and this causes the secondary windings within the coil to overheat and eventually burn out. And as the plugs deteriorate with age, the coil is forced to produce even more voltage to make a spark through the weak plugs. To lessen the chance of a coil going bad (again), set each plug gap at .015". The .015" gaps will simulate having just one spark plug with a gap of .030", and the coil will operate cooler and should last much longer. The engine will still start quickly, idle fine, run the same and produce just as much power as with the .030" gaps.

Or instead of doing the above È, if an older Briggs & Stratton twin cylinder flathead engine has points, it can be easily converted to the more reliable and powerful battery ignition (for a hotter spark). The B&S ignition points can be still used, but two automotive canister-type ignition coils or a battery ignition coil with dual plug terminals (as described above È) with spark plug wires, and two battery ignition condensers will need to be used. The spark plug gaps can be set at .035", and the ignition timing can be set by the width of the points gap (.020") or with an automotive inductive strobe timing light after the flywheel is degreed in with timing marks.

And if you're wondering if surface rust on flywheel magnets reduces magnetism and/or strength of the spark on the armature of a magneto ignition coil, well, I know for a proven fact that surface rust does not affect magnetism or strength of the spark whatsoever. (This is the same as saying that pure, undiluted automotive antifreeze coolant will freeze solid in freezing weather. It will NOT freeze! And despite of what you've probably heard, putting sugar in the gas tank will NOT ruin the engine! Read about it here: snopes.com: Sugar in the Gas Tank.) Don't just theorize about such things, believe in myths, rumors or what some [delusional] people/mechanics/technicians tell you. Perform a scientific test to prove to yourself and debunk the myths. I always do.

And for anyone who's wondering, an standard-output/ordinary automotive battery ignition condenser with an automotive canister ignition coil will work on any one- or two-cylinder air-cooled engine that use the battery ignition system. But when using two automotive ignition coils on a twin- or two-cylinder engine with conventional points, be sure to use two condensers as well, one for each coil , only if the coil(s) requires one. Otherwise, the engine will idle, but may not rev up. And there's a very little difference between the Kohler battery ignition condenser and an automotive [GM, Ford or Chrysler] ignition [points] condenser. So either can be used on a small engine.


What is the best spark plug to run in a garden pulling tractor, stock or otherwise?

Spark PlugFirst of all, avoid using a low cost, inferior quality or "cheapie" spark plug, especially with the wording "LAWN MOWER" printed on the porcelain! I never had one of these last more than 5 minutes in any engine. Also, when I began repairing lawn mowers in 1982, I've heard great things about NGK spark plugs, and in my experience, found that they are nothing but junk! I've had new ones foul-out when priming an engine with gas just to get it started! And if an engine did start, it would run for a couple of times before the plug became fouled. I've used Autolite and Champion non-resistor type spark plugs for the past 30+ years and they last A LOT longer. Also, avoid using resistor-type spark plugs in a small engine with magneto or solid state ignition. Resistor plugs will cause a good magneto or solid state coil to go bad prematurely because they force the secondary windings to produce voltage to the maximum to fire the plug, eventually causing the windings to burn up.

Try to avoid using a resistor-type spark plug with a suppression (carbon core) spark plug wire. Although these are designed to reduce nearby radio interference, they force the coil to build up much more voltage, and as the plug (and wire) deteriorate over time with use, the secondary windings within the coil will overheat, and possibly burn up, resulting in a failed coil. Also, it is definitely not considered "high performance" whenever a resistor-type spark plug and/or a suppression (carbon core) spark plug wire is used. Copper-core spark plugs, such as the Autolite 216 and Champion H10C, and OEM Kohler spark plug wires, which have metal core wire, are the best things to use either for general yard and garden work or for competition pulling. By using a copper-core plug and metal core wire, more voltage will reach the spark plug's tip, especially under high compression when the engine is running at wide open throttle, resulting in a hotter spark. With a copper-core spark plug and metal core spark plug wire, the coil will operate much cooler, too. I've seen pulling engines with a high-output/performance ignition coil, a resistor-type spark plug and a (fancy looking, brightly colored) suppression spark plug wire. This is defeating the purpose! All that's happening is a fraction of the voltage from the coil is reaching the spark plug. It'll be about the same as using a factory stock coil with a copper-core spark plug and a metal core spark plug wire. A stock, standard-output ignition coil with a solid metal spark plug wire and a copper-core spark plug will produce about the same amount of voltage at the spark plug's tip as a high-output/performance coil with a carbon core (suppression) spark plug wire and a resistor-type spark plug.

And in my experience, it seems that it makes no difference of what type of spark plug works best for either gas or methanol fuel. But a wider gap (.060") works better with methanol. And gas burns just fine with a standard gap of .035". Click here for Champion Spark Plug's Numbering System.

And the use of a "cold" or "hot" spark plug (heat range) doesn't matter in a pulling engine with a steel flywheel that have no fins because these engines have no cooling system to cool or extract the heat from the plug. When there's no fins on a flywheel or with an electric fan not running to cool the engine, nothing will cool the engine, except for a swift breeze on a cool, windy day.

Did you know that installing two spark plugs per cylinder doesn't help to increase the power output of an engine whatsoever? Simply because one plug will be running hot (exhaust side) and the other will be cool (intake side). Engine power is generated from the heat source, because heat is how an engine produces power. When the spark plug in the cylinder head is located over the exhaust valve, this maintains the majority of the heat in the combustion chamber in one area. When heat is maintained in one particular area in any given combustion chamber, the increase in power will be much greater, especially at high rpm. Burning fuel within a combustion chamber will "find" or locate the main heat source. The fuel will burn more thoroughly, allowing the engine to produce more power at any rpm. If the plug is located in the center of the combustion chamber, the incoming fuel could splash against the plug's tip and cause the engine to misfire or run erratic at high speed, especially when burning methanol fuel. And the plug could easily become fouled when burning gas, especially when the engine is cold. So it's best to install just one spark plug positioned over the exhaust valve with the plug gap set at .060". Because a .060" gap will simulate having two spark plugs. Use of a high-output/performance ignition coil will help produce a stronger spark, too.

Indexing the spark plug also helps to increase engine power and torque. This is when the open gap of the plug faces the center of the piston when the plug is torqued down. It helps in a more thorough combustion of the fuel so the engine will produce more power and torque at high rpms or at wide open throttle. An indexing washer is used to index a spark plug. They're of various thicknesses, made of copper (for heat transfer), and placed on the threads of the spark plug. The shims/washers for balance gears can also be used to index a spark plug. Place a line with a permanent felt tip marker (Sharpie) on the porcelain of the spark plug in-line with the open gap on the end of the plug. This is so you will know where the open gap is when the plug is installed. Indexing of the spark plug helps to increase the power and torque on a high performance engine that operates at high rpms or at wide open throttle. It doesn't help much on a stock or low rpm engine.

Also, when the spark plug in the cylinder head is located over the exhaust valve, this maintains the majority of the heat in the combustion chamber in one area, instead of being spread throughout the combustion chamber. When heat is maintained in one particular area in any given combustion chamber, the increase in power will be much greater, especially at high rpm. Burning fuel within a combustion chamber will "find" or seek out the main heat source. The fuel will burn more thoroughly, allowing the engine to produce more power at any rpm. If the plug is located in the center of the combustion chamber, the incoming fuel could splash against the plug's tip and cause the engine to misfire or run erratic at high speed, especially when burning methanol fuel. And the plug could easily become fouled when burning gas, especially when the engine is being choked or primed with fuel to start it when it's cold. Return to previous page or paragraph.

Advertisement:
If you need any of the items listed below Ê, please contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO 65203-9136 USA | Phone: 1-573-256-0313 (home/shop) | 1-573-881-7229 (cell/text). Please call Monday-Friday (except Holidays), 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Send a message with Yahoo Messenger: | Directions to our shop | Yahoo! Maps, 1501 W. Old Plank Rd., Columbia, MO | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest. Click here for more parts and services. | NOTE: To place an order, please call or send an email with a list and description of the parts or services you need. Because as of right now, we're not set up to accept orders through our web sites online. Due to the rising cost of... everything, prices are subject to change.
NOTE: All parts listed here are NEW, unless otherwise stated. I do not sell cheap junk! As a matter of fact, most OEM Kohler parts are made in China now. Kohler owns some of the factories in China that make the parts. And most aftermarket parts are also made by Kohler in China. Kohler just place the part(s) in a generic box and sell them for less money. So when purchasing a genuine OEM Kohler part that comes in a box with the Kohler name on it, you're really just paying more money for the name. And as far as some parts being no longer available - either the parts didn't sell well or the EPA is trying to phase out parts for the old cast iron block flathead engines because they produce more air pollution than the newer OHV engines.
Ignition points used on Kohler K-series engine models K90/K91, K141, K161, K181, K241, K301, K321, K330/K331, K341, K361, KT17, KT17II, KT19, KT19II, K482, K532 and K582. Also replaces Tecumseh: 32011, 32011A used on 6-20hp engine models HH80, HH100, HH120 series with battery ignition; Clinton engine models 414, 418, 420, 422. Each comes with mounting bracket. NOTE: Apply oil or grease on the hinge pin before installing points so the hole will last longer. When it's dry, it'll wear prematurely, effecting ignition timing, resulting in loss of engine power. Kohler part # 47 150 03-S. NOTE: The NOVA II, Mega-Fire or OEM Kohler Solid State Modules (below Ê) can be substituted for the points and condenser for a hotter and more stable spark, and virtually trouble- and maintenance-free magneto ignition system.
  • Aftermarket. $9.00 each, plus shipping & handling.
  • OEM Kohler part. $13.75 each, plus shipping & handling.
Chevrolet (GM) V8 adjustable ignition points that can be used on the Kohler K-series 10hp-16hp and twin cylinder flathead cast iron block engines. NOTE: The "Chevrolet" points and condenser are actually made for the 1955-1974 General Motors cars and trucks with a V8 engine and Delco-Remy distributor. But these points can be easily adapted for use on Kohler [pulling] engines with an adapter bracket for easy adjustment of the ignition timing with an Allen wrench. Points have a stiff spring for quick response at high rpm. Due to the inability to completely seal (cover) the point contacts from dust and debris, these are for competition pulling only, and not for general yard and garden use. And being the bracket for the GM points and the GM points themselves are much larger than Kohler points and bracket, the OEM Kohler points cover will not fit over the GM points and bracket.
  • Points only; does not include bracket. $10.00 each, plus shipping & handling.
  • For Chevy points mounting bracket and protective cover, contact Midwest Super Cub or Lakota Racing.
Standard capacity BATTERY ignition condenser used on Kohler K-series engine models K90/K91, K141, K161, K181, K241, K301, K321, K330/K331, K341, K361, KT17, KT17II, KT19, KT19II, K482, K532 and K582. NOTE: Use two ordinary, standard capacity condensers with a high-output/performance ignition coil. Wire length: approximately 4-1/2". IMPORTANT: Always install condensers with the wire or terminal facing down so rain water and/or when washing off engine, water will not enter into condenser, ruining it. Kohler part # 230722-S.
  • Aftermarket. $5.50 each, plus shipping & handling.
  • OEM Kohler part. $22.40 each, plus shipping & handling.
MAGNETO ignition condenser used on certain Kohler K-series engine models K141, K161, K181, K241, K301, K321, K330/K331 and K341. (Most common.) Body length: 33 mm, width: 17 mm. Same as condenser below Ê, except different mounting bracket. IMPORTANT: Always install condensers with the wire or terminal facing down so rain water and/or when washing off engine, water will not enter into condenser, ruining it. Kohler part # 47 147 01-S. NOTE: The NOVA II, Mega-Fire or OEM Kohler Solid State Modules (below Ê) can be substituted for the points and condenser for a hotter and more stable spark, and virtually trouble- and maintenance-free magneto ignition system.
  • Aftermarket. $5.00 each, plus shipping & handling.
  • OEM Kohler part. $21.10 each, plus shipping & handling.
MAGNETO ignition condenser used on certain Kohler K-series engine models K90/K91 and K241. Same as condenser above È, except different mounting bracket. IMPORTANT: Always install condensers with the wire or terminal facing down so rain water and/or when washing off engine, water will not enter into condenser, ruining it. Kohler part # 220434-S. NOTE: The NOVA II, Mega-Fire or OEM Kohler Solid State Modules (below Ê) can be substituted for the points and condenser for a hotter and more stable spark, and virtually trouble- and maintenance-free magneto ignition system.
  • Aftermarket. $15.00 each, plus shipping & handling.
  • OEM Kohler part. $16.00 each, plus shipping & handling.
Listed below Ê are the most common spark plugs for Kohler and other small engines. These have a copper-core, which help produce a hotter spark, plus they allow the coil to last longer. Spark plugs for other makes and models of small engines are also available. When ordering, please specify make and model of engine.

Quality Spark Plugs for Kohler engine models K90 (3.6hp), K91 (4hp), and most Briggs and Stratton and Tecumseh aluminum block flathead engines. 14mm threads x 3/8" thread reach, flat washer seat. Replaces Briggs and Stratton part # 802592S.

  • Autolite® 458. $2.50 each, plus shipping & handling.
  • Champion® J19LM. $3.20 each, plus shipping & handling.
  • OEM Kohler part # 41 132 06-S. $7.00 each, plus shipping & handling.

Quality Spark Plugs for Kohler engine models K141 (6¼hp), K140 (6.6hp), K161 (7hp) and K181/M8 (8hp). 14mm threads x 3/8" thread reach, flat washer seat.

  • Autolite® 295. Non-Resistor. $2.50 each, plus shipping & handling.
  • Champion® J8C. $3.20 each, plus shipping & handling.
  • OEM Kohler part # 41 132 02-S. $9.35 each, plus shipping & handling.

Quality Spark Plugs for Kohler engine models K241/M10 (10hp), K301/M12 (12hp), K321/M14 (14hp), K330/K331 (12½hp), K341/M16 (16hp) and K361 (18hp OHV). 14mm threads x 7/16" thread reach, flat washer seat.

  • Autolite® 216. Non-Resistor. $2.30 each, plus shipping & handling.
  • Champion® H10C. $3.20 each, plus shipping & handling.
  • OEM Kohler part # 25 132 10-S. $11.10 each, plus shipping & handling.

Quality Spark Plugs for Kohler twin-cylinder flathead engine models MV16, KT17, KT17II, KT19, KT19II, M18, MV18, M20 and MV20. 14mm threads x 15/32" thread reach, tapered seat.

  • Autolite® 26. $3.20 each, plus shipping & handling.
  • Champion® RV17YC. $3.65 each, plus shipping & handling.
  • OEM Kohler part # 52 132 02-S. $9.15 each, plus shipping & handling.

Quality Spark Plugs for most makes and models of OHV aluminum block single- and twin-cylinder air-cooled small engines. Replaces Briggs and Stratton part # 91055S. 14mm threads x 5/8" thread reach, flat washer seat.

  • Autolite® 3924. $2.70 each, plus shipping & handling.
  • Champion® RC12YC. $3.20 each, plus shipping & handling.
  • OEM Kohler part # 12 132 02-S. $6.10 each, plus shipping & handling.
Ignition Points Cover Gasket. Fits all cast iron block Kohler engines. Prevents dust, dirt and water from contaminating ignition points. OEM Kohler part # 52 041 11-S.
  • $1.65 each, plus shipping & handling.
Ignition Points Pushrod Diaphragm/Oil Seal. Prevents crankcase oil from contaminating ignition points. Fits all cast iron block Kohler engines with 3/16" diameter points pushrod. Seal slides over pushrod, and diaphragm is held in place by points bracket. Apply grease inside seal or on pushrod for lubrication. Made of clear vinyl rubber. OEM Kohler part # 220074-S.
  • $5.00 each, plus shipping & handling.
Ignition Points Cover Grommet. Fits all cast iron block Kohler engines. Protects wire from chafing and prevents dust, dirt and water from contaminating points. OEM Kohler part # 220297-S.
  • $3.30 each, plus shipping & handling.
Ignition Points Cover without Kill Button. Protects points from dust, dirt and water contamination. For cast iron block K-series Kohler engines with battery ignition. OEM Kohler part # 232535-S.
  • New. $10.45 each, plus shipping & handling.
Ignition Points Cover with Kill Button. Protects points from dust, dirt and water contamination. For cast iron block K-series Kohler engines with magneto ignition. OEM Kohler part # A-220136-S.
  • Used. $20.00 each, plus shipping & handling. (When available.)
  • New. $39.20 each, plus shipping & handling.
Stainless Steel Ignition Points Pushrod for Kohler K-series models K90/K91 (4hp). OEM Kohler part # 46 411 01-S.
  • $9.35 each, plus shipping & handling.

Stainless Steel Ignition Points Pushrod for Kohler K-series models K141 (6¼hp), K160 (6.6hp), K161 (7hp) and K181 (8hp). NOTE: To be no less than 1.250" in length. Measure length of your pushrod accurately to determine if it needs replacing. OEM Kohler part # 41 411 01-S.

  • $17.35 each, plus shipping & handling.

Stainless Steel Points Pushrod for Kohler K-series models K241 (10hp), K301 (12hp), K321 (14hp), K341 (16hp) and K361 (18hp OHV). NOTE: To be no less than 1.500" in length. Measure length of your pushrod accurately to determine if it needs replacing. OEM Kohler part # 47 411 04-S.

  • $13.40 each, plus shipping & handling.

Flared-End Stainless Steel Ignition Points Pushrod for Worn Points Lobe on Camshaft for Kohler K-series models K141 (6¼hp), K160 (6.6hp), K161 (7hp), K181 (8hp), K241 (10hp), K301 (12hp), K321 (14hp), K341 (16hp) and K361 (18hp OHV). Because of the length, please state engine model when ordering. Flared part makes contact with unworn sides of points lobe on camshaft for full advance of ignition timing. Can also be used with an unworn lobe for longer wear. NOTE: Must be installed from inside crankcase before engine reassembly. An innovative concept by Brian Miller. Replaces Kohler part # 47 411 04-S.

  • $15.00 each, plus shipping & handling.
Screws w/lock washers for fastening ignition points and points cover to engine block. Phillips head makes for easier mounting in hard-to-get places. Size: 10-24 NC x 3/8" (3/16" diameter x 3/8" thread length, coarse thread). Kohler part # X-131-1-S.
  • Aftermarket. Phillips head. .50¢ each, plus shipping & handling.
  • OEM Kohler part. $1.55 each, plus shipping & handling.

Allen head screws w/split lock washers for fastening ignition points and points cover to engine block. Allen head makes for even easier mounting in hard-to-get places. Size: 10-24 NC x 3/8" (3/16" diameter x 3/8" thread length, coarse thread). Replaces Kohler part # X-131-1-S.

  • Hardened black oxide steel. $5.00 per pair, plus shipping & handling.
Ignition Coil with Integrated Solid State Module for Kohler Magnum model M8 (8hp) single cylinder flathead cast iron block engine. Install with spark plug wire toward engine block. Kohler part # 41 584 03-S.
  • Aftermarket. $61.00 each, plus shipping & handling.
  • OEM Kohler part. $79.35 each, plus shipping & handling.
Ignition Coil with Integrated Solid State Module for Kohler Magnum models M10-M16 single cylinder flathead cast iron block engines. Install with spark plug wire toward engine block. Kohler part # 47 584 03-S.
  • Aftermarket. $60.00 each, plus shipping & handling.
  • OEM Kohler part. $78.35 each, plus shipping & handling.
Ignition Coil with Integrated Solid State Module for Kohler Magnum models MV16, M18, MV18, M20, MV20 twin cylinder flathead engines. Install with spark plug wires toward engine block. NOTE: Set spark plug gaps at .015" to prevent overheating the secondary windings and possibly causing premature failure of the coil. Kohler part # 52 584 02-S.
  • Aftermarket. $60.00 each, plus shipping & handling.
  • OEM Kohler part. $141.00 each, plus shipping and handing.
Ignition Coil with Integrated Magnetron™ Solid State Module for Briggs and Stratton's horizontal and vertical shaft models twin cylinder flathead engines. NOTE: Set spark plug gaps at .015" to prevent overheating the secondary windings and possibly causing premature failure of the coil. Briggs and Stratton part #'s 392329, 394891, 394988.
  • Aftermarket. $30.00 each, plus shipping & handling.
  • OEM Briggs and Stratton part. $45.00 each, plus shipping & handling.
Magneto Ignition Coil. Fits certain Kohler engine models K141, K161 and K181 with coil mounted on U-shaped stator on bearing plate underneath flywheel with rotor (rotating magnet) on crankshaft. Spark plug wire not included. Dimensions: 1.750" diameter x 1.450" length x .505" square hole. NOTE: The NOVA II, Mega-Fire or OEM Kohler Solid State Modules (below Ê) can be substituted for the points and condenser for a hotter and more stable spark, and virtually trouble- and maintenance-free magneto ignition system.
  • OEM Kohler part # 231718-S. $133.35 each, plus shipping & handing.

NOTE: The magneto coil wrapped with varnish-coated paper (Kohler part # 210293), and the stator assembly and rotor shown above are no longer available from Kohler. If you have an engine without these parts and you can't locate them from any source, your only option is to convert the engine to the battery ignition system. A small motorcycle battery or a rechargeable 12 volt sealed lead acid (SLA) battery with a minimum 4AH (Amp Hour) rating will need to be required to power the ignition, and with no charging system, a portable battery charger will need to be used to keep the battery fully charged when the tractor is not in use so the ignition will produce a hot spark. Avoid using a high-output/performance coil because these draw more amps from the battery.

Magneto Ignition Coil for engines with point/condenser ignition. For Kohler K-series flathead cast iron block, most smaller aluminum block Tecumseh and Clinton engines with coil/stator under flywheel. Replaces Tecumseh part #'s 29632, 30546, 30560, 30560A, 610768; Tecnamotor # 1633.0001; Kohler #'s 220435-S, 47 145 02-S, 47 755 20-S; Clinton # 135-13-990 and Phelon # FG-6240. Spark plug wire molded in coil. Spark plug wire length: 17". NOTE: Usually, the point gap sets at .020", but sometimes it will need to be set as close as .015" just to get a spark. This coil will work even better when used with the NOVA II, Mega-Fire or Kohler modules (see below Ê). The short wire on the coil is for ground, the longer wire connects to the points and condenser, and may need to be made longer depending on your application. Click here for identification and wiring diagram for this coil. Dimensions: .400" x .400" square hole (across flats) x 1.630" o.d. x 2.020" length (including spark plug wire hump). If laminations on your stator are too big for the hole in this coil, they can be ground or filed smaller so coil will fit snug, then bend one laminate over to retain coil, or if the laminations are too small, thin strip(s) of steel can be added so coil will fit snug, and coil should produce a hot spark. The coil must fit snug on the laminations to receive the full effect of the magnetic field through the stator from the rotating magnet(s) to fully energize the coil. Do not enlarge the hole in the coil! How magneto coils produce a spark. NOTE: The NOVA II, Mega-Fire or OEM Kohler Solid State Modules (below Ê) can be substituted for the points and condenser for a hotter and more stable spark, and virtually trouble- and maintenance-free magneto ignition system.
  • Aftermarket. $25.00 each, plus shipping & handling.
  • OEM Kohler part #'s 220435-S, 47 145 02-S, 47 755 20-S. $99.55 each, plus shipping & handling.
NOVA 2, Mega-Fire and OEM Kohler Electronic Transistorized Solid State Ignition Modules [Return to a previous section]
  • There is absolutely no difference how these modules work. They all work the same. Kind of like the difference between the Chevy, Dodge and Ford vehicles. These are universal and high performance. They improve engine performance by stabilizing the spark, much like crank trigger ignition does. The NOVA 2 and Mega-Fire modules have a durable die-cast aluminum housing. They all produce a hot spark even at cranking speeds, allows the coil to produce 100% voltage. Weather-proof and very reliable. Ignition timing is automatically set. No kick-back and no timing adjustment required. Works excellent with virtually any magneto ignition coil!
  • Suitable for use with most 2 leg or 3 leg magneto coils and with a flywheel having one or two magnets mounted internally or externally, and with coil mounted underneath or outside of flywheel. Works great regardless of the polarity of the magnets, too. Works on most lawn mowers, chain saws, trimmers, garden tillers, snow throwers, brush cutters, one or two cylinder outboard boat motors, etc., with points and condenser ignition. But will not work with most Stihl trimmers and chain saws. Usually, the coil don't need replacing when substituting the points and condenser with one of these solid state modules. If the engine ran, then the coil is obviously good.
  • Works only with magneto type ignition coils originally connected to contact points and a condenser. They will not work with solid state ignition (CDI) coils, battery ignition coils or with flywheels having a ring of magnets mounted internally to which the ignition coil (mounted underneath flywheel also) operates off of, such as the bigger aluminum block Tecumseh engines (8hp and up). (With the module, as each magnet passes the coil, it'll produce a spark. And if the spark don't occur at the precise time with the piston at a certain position in the cylinder, the engine will either "kick back" or will not run.) If the magnets for the charging system won't interfere with the magneto coil(s), then these modules should work well. But if the magneto coil(s) operate off the same magnets for the charging system, then neither module won't work. The modules senses when the magnet passes the coil and that's when it makes the spark. If a bunch of magnets continually pass the coil, then the coil will produce an array of sparks.
  • How the timing is automatically set and how it works: First of all, with points, the point gap determines where the ignition timing is set (on systems with a fixed or non-adjustable ignition coil). Therefore, the spark occurs when the magnet in the flywheel passes the coil laminations the moment the points open. But with no points, the magnet still passes the coil laminations at the same moment, which sends an electrical current through a transistor and circuitry within the NOVA 2 module. This current is sent in the form of a signal to the module; within, a transistor opens the primary circuit in the coil and the spark occurs. All this happens at the speed of electricity. The conventional points and condenser ignition system is less responsive.
  • Each module has two wire connections. One wire connects to the ignition coil and the other wire connects to the ground of the engine with use of a supplied mounting screw. Comes with detailed instructions. Click here for installation instructions.
    • NOVA 2 Module. $17.00 each, plus shipping & handling.
    • Mega-Fire Module. $20.00 each, plus shipping & handling.
    • Kohler Module. OEM Kohler part # 25 757 10-S. $48.00 each, plus shipping & handling.
Briggs & Stratton's Magnetron™ Solid State Ignition Module. An alternative to using the NOVA 2 or Mega-Fire modules. Installs next to the external two-armature ignition coil that use points and condenser. Provides a hotter and more stable spark than points ignition. Installation instructions included. Will not work with the older three-armature coil or any other type of coil. If swapping the three-armature coil for a newer two-armature coil, a newer flywheel will need to be used, too. NOTE: If no spark after installing the Magnetron™, the magnets in the flywheel will need to be re-polarized by Briggs & Stratton.
  • OEM Briggs & Stratton part # 394970. $22.00 each, plus shipping & handling.
Heavy Standard-Output/Ordinary (20,000 volts) 12 Volt Canister Oil-Filled Ignition Coils. These coils can be used with one ordinary, standard capacity condenser. Spark plug gap should be set at .035". Can be used on most garden tractors, older farm tractors, pulling tractors and with crank trigger ignition systems. Bracket included. NOTE: These coils have an internal 1.5 ohm resistor to prevent premature burning of ignition points. And most failures of battery ignition coils is caused by overcharging of electrical system due to faulty [automotive] battery or faulty voltage rectifier/regulator. Or the use of carbon core (suppression) spark plug wires and/or a resistor spark plug will also cause a good coil to eventually fail because the secondary windings within the coil overheat and eventually burn up from producing excessive voltage to fire the plug. This is why I recommend the use of metal spark plug wires and copper-core spark plugs. I have seen too many good high dollar coils fail because the wrong parts was used. Kohler part # 41 519 21-S.
  • Aftermarket. $25.00 each, plus shipping & handling.
  • OEM Kohler coil. $68.00, plus shipping & handling.
High-Output/Performance (40,000 volts) 12 Volt Oil-Filled Canister Battery Ignition Coil. Suited for high performance engines. Spark plug gap can be set at .060". Can be used on later model automobiles, most garden tractors, older farm tractors, pulling tractors and with crank trigger ignition systems. High quality. Made by various manufacturers. Bracket not included. NOTE: This coil requires an external ballast resistor to prevent premature burning of ignition points and two ordinary, standard capacity condensers or one high capacity/performance condenser (Accel or Mallory) so coil will produce full voltage. And most failures of battery ignition coils is caused by overcharging of electrical system due to faulty [automotive] battery or faulty voltage rectifier/regulator. Or the use of carbon core (suppression) spark plug wires and/or a resistor spark plug will also cause a good coil to eventually fail because the secondary windings within the coil overheat and eventually burn up from producing excessive voltage to fire the plug. This is why I recommend the use of metal spark plug wires and copper-core spark plugs. I have seen too many good high dollar coils fail because the wrong parts was used.
  • $35.00 each, plus shipping & handling.
New 1.6 Ohm Ballast Resistor for high-output/performance ignition coils above È to prevent burning up ignition points or Chrysler electronic ignition control module to prevent burning up the module.
  • $7.00 each, plus shipping & handling.
Battery Ignition Coils for Kohler flathead twin cylinder models KT17, KT17II, KT19, KT19II, KT21 engines. NOTE: Most failures of battery ignition coils is caused by overcharging of electrical system due to faulty [automotive] battery or faulty voltage rectifier/regulator. Or the use of carbon core (suppression) spark plug wires and/or a resistor spark plug will also cause a good coil to eventually fail because the secondary windings within the coil overheat and eventually burn up from producing excessive voltage to fire the plug. This is why I recommend the use of metal spark plug wires and copper-core spark plugs. I have seen too many good high dollar coils fail because the wrong parts was used. Kohler part # 52 755 48-S.
  • Aftermarket coil without aftermarket spark plug wires. $114.00 each, plus shipping & handling.
  • Aftermarket coil with aftermarket spark plug wires. $146.00 each, plus shipping & handling.
  • OEM Kohler coil without OEM Kohler spark plug wires. $190.15 each, plus shipping and handing.
  • OEM Kohler coil with OEM Kohler spark plug wires. $225.10 each, plus shipping and handing.

Spark Plug Wires for above È coils. NOTE: The OEM Kohler spark plug wires rarely go bad or get weak. The only time they need replacing is when damaged beyond use.

  • Kohler part # 52 348 03-S. 11" long. (for #2/left cylinder when facing flywheel.)
    • Aftermarket. $9.00 each, plus shipping and handing. (When available.)
    • OEM Kohler part. $16.75 each, plus shipping and handing.
  • Kohler part # 52 348 04-S. 19" long. (for #1/right cylinder when facing flywheel.)
    • Aftermarket. $9.00 each, plus shipping and handing. (When available.)
    • OEM Kohler part. $18.20 each, plus shipping and handing.
Battery Ignition Coil for Kohler twin cylinder engine models K482, K532, K582, K660/K662 and Harley-Davidson motorcycles. Has internal 4 ohm resistor. NOTE: Most failures of battery ignition coils is caused by overcharging of electrical system due to faulty [automotive] battery or faulty voltage rectifier/regulator. Or the use of carbon core (suppression) spark plug wires and/or a resistor spark plug will also cause a good coil to eventually fail because the secondary windings within the coil overheat and eventually burn up from producing excessive voltage to fire the plug. This is why I recommend the use of metal spark plug wires and copper-core spark plugs. I have seen too many good high dollar coils fail because the wrong parts was used. Kohler part # 277375-S. Also replaces Harley-Davidson part # 31609-80.
  • Aftermarket. $100.00 each, plus shipping and handing.
  • OEM Kohler part. $217.55 each, plus shipping and handing.
Complete 7mm diameter Spark Plug Wires with boots and terminals for above È coils. NOTE: The OEM Kohler spark plug wires rarely go bad or get weak. The only time they need replacing is when damaged beyond use. Also, the terminals and boots aren't on one end of the aftermarket spark plug wires. The terminal and boot for the spark plug is installed on one end and each wire will need to be safely routed from the plugs to the coil, allow some length for flexibility, and cut off the excess wire. Then install the boot on each wire that fits your coil best, strip off about 1/2" of insulation, bend the wire over, install the terminal on the insulation/wire, then lightly crimp the terminal with pliers. The squeezing pressure of the terminal/insulation in the coil tower insures the wire will stay in the terminal.
  • For K90 through K361, K482, K532, K582 and K660/K662 engines with battery ignition. 25-1/2" long. Kohler part # 238057-S.
    • Aftermarket. Stranded copper-core wire. $10.00 each, plus shipping & handling.
    • OEM Kohler part. $33.90 each, plus shipping & handling.
  • For K90 through K361 engines with battery ignition. (Unknown length.) OEM Kohler part # 41 348 06-S. $18.20 each, plus shipping & handling.
  • For K90 through K361, K482, K532, K582 engines with battery ignition. (Unknown length.) OEM Kohler part # 48 348 03-S. $25.00 each, plus shipping & handling.
  • For K482, K532 and K582 engines with battery ignition. (Unknown length.) OEM Kohler part # 48 348 04-S. $20.60 each, plus shipping & handling.
Spark Plug Grommet for Kohler "Quiet Line" engine models K181AQS, M8, K241AQS, K301AQS, K321AQS and K341AQS. Fastens directly on spark plug in air duct shield (sheet metal) over cylinder head. Made of neoprene rubber. OEM Kohler part # 47 313 01-S.
  • $3.95 each, plus shipping & handling.
Magneto Ignition-to-Battery Ignition System Conversion Kit. Convert virtually any single cylinder, air-cooled cast iron or certain aluminum block small gas engine that originally came with a magneto ignition system (having points, condenser and ignition coil that has voltage generated by a set of permanent magnets in the flywheel, instead of being powered by a battery) into the battery ignition system. FYI: Battery ignition conversion is mainly intended for older engines when the magneto coil and/or other ignition parts are no longer available or they are very expensive (cost prohibitive). Also, the most hassle when using battery ignition without a charging system integrated with the engine is the use of a remote battery charger. And eventually a new battery will need to be purchased, because they only last a few years. Parts include: new heavy duty aftermarket standard output (20,000 volts) canister ignition coil with internal 1.5 ohm resistor, aftermarket battery-type condenser and aftermarket 25-1/2" long 7mm copper-core spark plug wire. NOTE: Use the OEM points, set the gap at .020" or the timing at 20° BTDC and reuse the same type of spark plug, but set the gap at .035" for a hotter spark. Click here for wiring diagrams.
  • Complete kit. $40.00 each, plus shipping & handling.


Kohler Breakerless Ignition-to-Battery Ignition System Conversion Kit. Parts includes: Aftermarket ignition points, aftermarket battery-type condenser, heavy duty aftermarket standard output (20,000 volts) ignition coil with internal 1.5 ohm resistor (existing spark plug wire can be reused), OEM Kohler points pushrod, OEM Kohler points cover, OEM Kohler points cover gasket, OEM Kohler points cover/wire grommet, and four aftermarket 10-24 NC screws to fasten points and points cover to engine block.

  • Complete kit: $70.30 each, plus shipping & handling.
New points, condensers and spark plugs for other makes and models of engines are also available. Please call or email me for your needs.

How to Set the [Point] Ignition Timing on Virtually Any Small Gas Engine - Top of page

First of all, widening or narrowing of the points gap is how the ignition timing is adjusted. Widening the gap advances the timing and narrowing it retards the timing. On a Kohler engine, adjust the points by first positioning the piston at TDC on the compression stroke. Then slightly loosen the set screw on the points and place the flat screwdriver in the slot on the upper part of the points bracket to widen and narrow the point gap. Then use a .020" feeler gauge to set the gap. If the screw that fastens the points to the bracket is hard to get at with a screwdriver on the equipment, then install an Allen head screw and use an angled Allen wrench to loosen and tighten the screw that clamps the points in place.

The point gap on virtually all 4-cycle small gas engines, rather if it has one or two cylinders, is set at .020" using a feeler gauge with the piston positioned at TDC on the compression stroke. This is when the valves (#1 cylinder for a twin cylinder) are fully closed. This sets the ignition timing approximately at 20° BTDC (Kohler engines), and is the most easiest and simplest way to basically set the timing. A better way is to statically set the timing. But the most accurate way is use an automotive inductive strobe timing light to dynamically set the timing.

To statically set the ignition timing on an engine with points, condenser and a stock flywheel, use an analog multimeter set on OHMS [d] resistance or a 12 volt test light and a 12 volt power source to power the light. To make this happen...

  1. Connect one lead of the multimeter or test light to the ignition points terminal screw or the points wire (disconnect it from the ignition coil first) and the other lead to engine or tractor ground so that the points will serve as a switch to activate the meter or light. To test the connection, set the points gap at .020" with a feeler gauge and then slowly rotate the crankshaft (flywheel) back and forth when the points open and close to see if the meter is activated or light comes on and goes off. IMPORTANT: Never use sandpaper or emery cloth to clean ignition points! They'll leave grit between the contacts (which is hard to remove after it's burned in the contacts) and cause a bad connection. Always clean new or used points contacts with a wire wheel, quality steel fingernail file, a "small ignition point file", which is a small, thin steel special purpose file, to remove any oxidation (light corrosion) that can form on the platinum surface while in storage. If this isn't done, it could cause a faulty connection and a weak or no spark situation. Then after cleaning the gap with the file, place a clean piece of white lint-free [notebook] paper between the points contacts, close the gap by rotating the crankshaft and then slowly drag the paper through the contacts to remove any debris that may be on the contacts.
  2. On Kohler flywheels, there should be a T and an S stamped into the edge of the flywheel. Place a bright colored paint mark on the S mark [punched line]. S stands for Spark Advance, is located exactly at 20° BTDC, which is where the timing is set if the engine is equipped with a one-piece camshaft that originally came with a compression release mechanism. T stands for TDC, which is where the timing sets if the engine is equipped with an older two-piece camshaft with an automatic timing advance. If there's a timing site hole in the rear of the bearing plate, then the timing marks are on the backside of the flywheel. If the marks can't be seen, then the flywheel will need to be cleaned off and depending on type of camshaft, a bright colored paint mark needs to placed at the T (older two-piece camshaft w/automatic timing advance) or S mark (newer one piece camshaft w/automatic compression release). If there is no visible S mark, then it's located exactly 1-5/8" (1.625") above or before the T mark. Steel flywheels with no timing marks must be degreed-in with a degree wheel and piston stop to create new timing marks.
  3. Slowly rotate the flywheel back and forth by hand when the timing marks are aligned with the center of the site hole or raised mark on the bearing plate and at the same time observe the ohmmeter or test light. The ohmmeter should show an intermittent connection or the test light should flicker. If necessary, widen or narrow the points gap until the points make contact the exact moment the timing marks are aligned. It is at this position when the ignition timing is statically and accurately set.
  4. Timing for gas fuels can vary from 20°-22° BTDC for low octane; 100% automotive gas, to 30° BTDC for high octane race gas, aviation gas, or automotive gas w/10% alcohol.
  5. Timing for E-85 - 25° BTDC.
  6. Timing for METHANOL fuel - if the spark plug is positioned in the center of the combustion chamber, set the timing at 24-26° BTDC. If the plug is located closer to the exhaust valve, the timing needs to be set around 30° BTDC. And if the plug is directly over the exhaust valve, the timing needs to be set at 38° BTDC to obtain full power. 38° BTDC is the maximum setting for methanol or gas fuels.
  7. It'll be a good thing to check the ignition timing periodically as the points contacts wear.

The most accurate way to set the timing is to use an inductive automotive strobe timing light through the site hole in the flywheel shroud with the engine running at an idle to see the painted "S" mark on the flywheel and the raised mark on the bearing plate. When the marks are aligned, the timing is set at 20° BTDC. This cannot be done with an aftermarket steel flywheel having no timing marks.

The ignition timing greatly depends on where the spark plug is located in the combustion chamber. Most plugs are centered in the combustion chamber. But if it's closer to the exhaust valve, the timing must be advanced slightly more. Location of the spark plug in the combustion chamber and proper ignition timing are two things that's very important in engine performance. Actually, it's best to set the timing with some test pulls or with the engine connected to a dynamometer or "engine dyno."

NOTE: If the ignition timing is set right and the engine kicks back when trying to start, sometimes, but not always, the compression release isn't releasing enough compression from the combustion chamber. Try setting the valve clearances to specs and see if that makes a difference. If the timing is retarded to reduce the possibility of kickback, then the engine will run sluggish and not produce enough power. Return to a previous page or paragraph. Return Ê

Isn't it a pain having to constantly adjust or set the ignition timing on a Kohler pulling engine? To fix this problem, I think the best ignition points to use for a Kohler pulling engine are ordinary Kohler points. The spring on Kohler points is much stiffer than the one on the Chevrolet (GM) V8 ignition points. I realize that Chevy points are fancy to show off and convenient because they make it so much easier to adjust the ignition timing, but due to normal engine vibrations on a single cylinder engine, they're prone to get out of adjustment. And it's difficult (if at all possible) to lock the adjusting screw in position. If [blue] Loctite is used, this would make them non-adjustable. The clamping screw on Kohler points on the other hand, locks in position, the adjustment won't slip due to normal single cylinder engine vibration. (A short Allen head screw should be used for easier accessibility to adjust the points.) Also, unlike Chevy points, Kohler points are easier to cover (use the OEM Kohler points cover) to keep the contacts clean and to prevent a fire.

Another simple way to set the ignition timing is to use a dial indicator to measure the distance of the piston from the top of the block. On the 10hp Kohler engines, the points just begin to open when the piston is located exactly at .125" BTDC. And on the 12, 14, 16hp flathead engines and 18hp OHV engine, the points just begin to open when the piston is located exactly at .100" BTDC. Distances shown is when the S mark on the flywheel is aligned with the mark on the bearing plate. Take into consideration if the piston doesn't come flush with the top of the block, or if it protrudes out of the cylinder. EXCEPTION: When setting the ignition timing on an older Kohler engine with the old style two-piece camshaft, set the points so they just begin to open with the piston positioned on the compression stroke at 0° TDC (T mark on the flywheel). As soon as the engine starts, the points lobe rotates on the cam pin and flyweights on the cam gear automatically advances the timing to 20° BTDC. Don't set the initial timing at 20° BTDC (S mark) with the old style two-piece camshaft. Due to the absence of a compression release (these engines start under full compression), setting it at 20° BTDC will advance the timing too much and cause the engine to "kick back" when attempting to start the engine. "Kick back" occurs when the flywheel/crankshaft suddenly and violently rebounds or momentarily rotates in the opposite direction, which is could bend or break the starter armature shaft or the aluminum starter housing.

How To Read A Dial Indicator -

Dial IndicatorEach mark on the face of a dial indicator represents one thousand of an inch (.001") graduations. The marks with a number (10, 20, 30, etc.) represents every ten thousands (.010"). Depending on the size of the engine, for a reading of .050" or .070" BTDC, first, run the piston up at true TDC, then set the dial indicator at the .050" or .070" mark. Then, slowly rotate the crankshaft in opposite of normal engine rotation until the needle reads 0 degrees BTDC. The needle will move in the counterclockwise direction (back to the 0 degree mark) as the piston moves downward in the cylinder.


Differences in Kohler's flywheel shroudsWhere is the Timing Site Hole in the Flywheel Shroud?

On the small [8"] flywheel without the starter ring gear and with the starter/generator, the timing site hole is on the right when facing the front of the flywheel, or on the same side as the starter/generator. But on the large [9-1/2"] flywheel with the starter ring gear and gear starter, the timing site hole is on the left when facing the front of the flywheel, or on the same side of the carburetor.

To set the ignition timing on the 7hp and 8hp Kohler engines, there's a sight hole in the backside of the bearing plate on the starter/generator side, just behind the flywheel. It has a metal hole cover plug in it. Remove the plug and then slowly rotate the flywheel by hand until you see the S mark. Place a white paint mark on the line. Now connect an automotive inductive strobe timing light, start the engine and then note if the mark appears midway in the sight hole. If not, adjust the points until the mark is centered in the hole. This is how you set the ignition timing with a timing light.

It is recommended that a steel flywheel be degreed in on an engine to locate true TDC. Mark the flywheel every 5 degrees out up to 35 degrees BTDC. Note: With a steel cam and ground-on point lobe, do not correlate points gap with engine timing – there is a range from approximately 10 degrees BTDC to 40 degrees BTDC! Use a continuity tester to set points to desired ignition timing by gapping points.

Ignition timing must be properly set for any engine for it to produce full power. Ignition timing is set according to when the piston reaches its Before Top Dead Center (BTDC) position in the cylinder on the compression stroke. When measuring the piston distance, take in consideration if a piston protrudes out of the cylinder or if it doesn't come flush with the top of the block. And don't trust strange markings on the flywheel.

For precise accuracy, use an ohmmeter or a test light in the points circuit, a dial indicator to measure the distance of the piston in the cylinder, fasten a degree wheel to the crankshaft flywheel end and you'll need to fabricate a piston stop. On a flathead engine, to serve as a piston stop, a long reach spark plug can be used, and the cylinder head must be positioned so the spark plug is over the piston.

Tools Needed to Accurately Set the Ignition Timing -

Degree Wheel

The degree wheel is a round disc (usually made of aluminum) with the facing edge marked off in degrees, similar to the markings on a protractor. When used in conjunction with a dial indicator, it's installed on the crankshaft during the engine build to degree the cam in and check for correct valve timing events. It can also be used to check for accurate ignition timing. When in use, a degree wheel is fastened to the front of the crankshaft (automotive engines) or flywheel end (small engines). If it's fastened to the PTO end, it will need to face the engine block and be read from that position. Degree wheels can be purchased off of eBay.

Dial Indicator and Magnetic Base

A dial indicator is necessary to check for correct valve timing to tell precisely when a valve starts to open and the moment it closes. This opening and closing is very critical for high performance engines and cannot be done by feel or by sight. A dial indicator can also be used to set accurate ignition timing in relation to piston travel. Each mark on the face of a dial indicator represents one thousandth of an inch (.001") graduations. The marks with a number (10, 20, 30, etc.) represents every ten thousandths of an inch (.010", .020", .030", etc.). A dial indicator always mounts on top of the engine block. Dial indicators are very precision and delicate instruments. Care must be used in handling one. Dial indicators can be purchased from LittleMachineShop.com.

Piston Stop Tool

A piston stop tool is used to accurately find the piston's true Top Dead Center (TDC). For a multi-cylinder engine, the piston stop is always used on the #1 piston, which is closest to the front of the engine block.

To make a simple piston stop for a flathead engine, if the spark plug is perpendicular with the head, an old, long-reach (long threaded) spark plug can be used in the head for a bump-stop. Simply position and fasten the head on the block with the plug directly over the piston. The spark plug can be adjusted up or down to find the top dead center of the piston in relationship with the degree wheel. A steel rod may need to be welded on the end of the plug for an extended reach.

Or for a universal flat bar type of piston stop, the bracket part should be made of minimum 1/4" thick x 1" wide flat steel or aluminum, drilled with a couple of holes so that it can be fastened to the top of the block with a couple of head bolts, directly over the piston. A minimum 1/4" bolt with a jam nut, threaded upside-down into the bracket is also required. The adjustment of the bolt is used to "stop" the piston. If a piston protrudes out of the cylinder at TDC, then to use a piston stop, install several spacers (flat washers) between the piston stop and engine block so the bracket will clear the piston and go past the TDC mark.

A dial indicator, degree wheel and piston stop are also used in degreeing in the camshaft. Check your local automotive parts supply stores for a 12 volt test light, dial indicator and degree wheel. If they don't have them in stock, they can probably order them for you.

With an aftermarket steel flywheel or a stock flywheel with no timing marks, the most accurate way to set the ignition timing [on virtually any engine] is performed by measuring the distance of the piston before it reaches top dead center with a dial indicator in conjunction with a degree wheel fastened to the crankshaft flywheel end. To learn more, read on....

Find TRUE Top Dead Center (TDC) on an Engine with a Steel Flywheel to Accurately Set the Ignition Timing! Parts needed are a degree wheel and a piston stop. Or on a flathead engine, a long reach spark plug can be used, and the cylinder head can be positioned it so the spark plug is over the piston.

  1. Connect the ohm meter or test light as described above È.
  2. Remove the cylinder head from the engine.
  3. Fashion a rigid pointer from stiff wire or an old coat hanger and attach it to the engine block. This pointer locates the degrees on the degree wheel.
  4. With a degree wheel installed on the flywheel or PTO end of the crankshaft, and with the flywheel fastened onto the crankshaft, rotate the crankshaft by hand in normal running rotation until the piston at the very top of the cylinder with both valves fully closed (this is the Top Dead Center position on the compression stroke), and then adjust the pointer to zero (0º TDC) on the degree wheel.
  5. Now turn the crankshaft opposite the running rotation approximately 15-20 degrees. Install a piston stop on the top of the engine block fastened in place by two head bolts. NOTE: If a piston protrudes out of the cylinder at TDC, then to use a piston stop, you'll need to install several flat washers or a spacer between the piston stop and engine block so the piston will clear it and go past the TDC mark.
  6. Continue to turn the engine in the same direction until the piston comes back up and just touches the piston stop. Make a note of the exact number on the degree wheel that the pointer is on.
  7. Rotate the engine in the other direction (running rotation) until the piston comes back up and touches the piston stop. Again note the number where the pointer is.
  8. Remove the piston stop and rotate the crankshaft to the midpoint of the two marks. At this point the piston is at the true top dead center. Loosen the degree wheel and adjust it so it will read 0º TDC at the pointer. Don't rotate the crankshaft to do this!
  9. Slowly rotate the engine in reverse normal rotation. The test light should be on. If not, adjust the points so it is on.
  10. Rotate the crankshaft by hand in its normal direction until the degree wheel is where you want the timing to be set at (20º) and then adjust the points so they just begin to open. The test light should've gone off or flickered by now. If not, set the points so they just start to open and the light flickers. Once the degree wheel is in the proper position, the breaker points should just begin to open. Or, when using Crank Trigger Ignition, check or set the initial timing by positioning the center of the magnetic pickup coil or inductive proximity sensor with the center of the trigger screw or small raised area of the rotating disc. It is at this moment when spark occurs. And it's at this point that the ignition timing is set correctly. Mark the flywheel or front pulley where the timing marks are on the degree wheel for setting the timing with an automotive inductive strobe timing light in the future.
    FYI - Inductive Proximity Sensors requires external power and functions with three wires: blue (power+), brown (power+) and black (signal). They come in two versions: Normally Open (NPN) and Normally Closed (PNP). On models equipped, the LED sensor will illuminate when energized. This tells you that it's working. A Normally Open sensor produces electrical current to the ignition module only when it comes in close proximity of a detectable ferrous metal (steel) object, then the circuit is closed (LED sensor comes on). Normally Open sensors are used mainly for crank trigger ignition systems on gas engines. A magnetic pickup coil works like a Normally Open (NPN) sensor. Inductive proximity sensors also work almost like metal detectors; if the metal comes close enough to the sensor, an alarm will sound. But a Normally Closed sensor works opposite. They produce electrical current to the module at all times (LED sensor goes off) while external power is supplied to it except when it comes in close proximity of a detectable ferrous metal object, then the circuit is opened (LED sensor comes on). Normally Closed sensors are used mainly in places where security is needed. They can be used for exterior windows or doors in a building. When a window or door with a detectable ferrous metal object is moved away from the sensor, the circuit will be closed and an alarm will sound and/or lights will come on. If an inductive proximity sensor has no markings or indications to show that it's a PNP or NPN, a 100% sure way to determine the type, is to test it with wires connected in a circuit (as shown in the drawings further down Ê), bring a steel object close to it, then observe for spark at the spark plug's tip. NOTE: If a Normally Closed Inductive Proximity Sensor is wired incorrectly, the LED sensor will stay ON and go OFF when activated. (Normally Open sensors will work as Normally Open.)

Setting the Ignition Timing with an Automotive Non-Inductive or Inductive Strobe Timing Light -

NOTE: The above È method is sufficiently accurate and useful in building a fresh engine and not having to mess with adjusting the points just to get the engine started for the first time. However, after getting the engine started, it's always a good thing to use either an automotive non-inductive or inductive strobe timing light to check to see if the timing is truly set where it's supposed to be. This is called setting the timing dynamically. Use a timing light when the timing marks on both the bearing plate and flywheel are perfectly aligned. The ignition timing setting for Kohler engines burning GAS is 20-22° BTDC. NEVER run over-advanced timing (beyond the 22° setting) with gas just to try to get "more power" out of an engine! All that'll do is seriously overheat the engine and ruin parts. Return to previous paragraph. Ê

To use a non-inductive strobe timing light (these are very old and are considered obsolete), connect one lead on the spark plug (on a twin cylinder engine, connect it on the #1 cylinder spark plug) and the other on the coil, and then start the engine.

To use an inductive strobe timing light, the engine can be running while connecting the clamps on the battery posts in their respective order, and then connect the inductive pickup on the spark plug wire. On a twin cylinder engine, connect it on the #1 cylinder spark plug wire. (The #1 cylinder is the one closest to the flywheel.) If using an inductive strobe timing light with an advance adjustment, make sure it's set at 0 (zero) before checking the timing on the S mark.

If an engine has a compression release on the camshaft and the valve clearance is set right (at least for the exhaust valve), chances are the engine will not "kick back" when attempting to start the engine. "Kick back" occurs when the flywheel/crankshaft suddenly and violently rebounds or momentarily rotates in the opposite direction, which is could bend or break the starter armature shaft or the aluminum starter housing. Therefore, this would be a false indication that the timing is set correctly. Always check it with a timing light to make sure!

The ignition on Kohler engines aren't like the ignition on most automotive engines. You don't dwell-in the points on a Kohler engine. Instead, you set the point gap at .020" as the initial setting just to get the engine running. Then the ignition timing is set by widening or narrowing the points gap until the timing is at 20° BTDC by observing the alignment timing marks on the flywheel.


How to set the [point] ignition timing on older Tecumseh engines - Top of page
First of all, on virtually any spark-ignition engine, advancing or retarding of the ignition timing is performed by widening (advancing) or narrowing (retarding) the ignition point gap, and on Tecumseh engines, it's also performed by rotating the stator. (The thing the points, condenser and coil are fastened to.) On a Tecumseh engine, the points gap is supposed to be set on the high spot of the rubbing block or points lobe that's on the crankshaft, located underneath the flywheel. There are no points lobe on the camshaft.
  1. Using a feeler gauge, set the ignition points at 020". NOTE: Be sure the plastic lever arm is on the high side of the rubbing block (point lobe) where the arrow or "6" is. And make sure that the feeler gauge and point contacts are absolutely clean! Also, apply a small dab of grease on the rubbing block to prevent the plastic lever from wearing.
  2. With the cylinder head removed, for all Small Frame engines (up to the small block 5hp; including all walk-behind lawnmowers, some small snowblowers, garden tillers, etc.), rotate the crankshaft in normal rotation (clockwise when facing the flywheel) until the piston is positioned at .070" BTDC. For all Medium Frame 5hp [big block] and 6hp cast iron and aluminum block engines, position the piston at .050" BTDC. And for the Medium Frame 7hp, 8hp and 10hp aluminum block engines, position the piston at .090" BTDC. Use either a dial indicator or a large flat washer of specified thickness to measure the piston height in the cylinder.
  3. Loosen the two stator bolts and then rotate the stator by hand JUST when the points begin to open. It is at this point when spark occurs. Do not rotate the crankshaft to do this! You can visually see the points or for a more accurate setting, use a test light or ohm meter to check the "breaking" of the points.
  4. Tighten down the stator bolts and the ignition timing is set.

NOTE: If the ignition timing is set right and the engine kicks back, sometimes, but not always, then the compression release isn't releasing enough compression. Try setting the valve clearances to specs and see if that makes a difference. If the timing is retarded to reduce the possibility of kickback, then the engine will run sluggish and not produce enough power.


How to Fix the Problem with a Worn Points Lobe on the Camshaft -

Sometimes the points lobe on a single cylinder Kohler camshaft will become worn or have a groove worn into it so badly that the ignition timing can't be advanced enough to get adequate power out of the engine. There's a way to fix this, and there's no need to purchase another camshaft or do welding on the points lobe. Simply install a nut on the pushrod. The nut will make contact with the outer unworn areas of the lobe, allowing full advancement of the timing as if the lobe wasn't worn at all. To fix the problem with a worn points lobe...

  1. Completely disassemble the engine and remove everything from inside the crankcase.
  2. Acquire a hardened steel 10-24 NC or 10-32 NF (thread size) x 3/8" (wrench size) hex nut.
  3. Cut very short threads perpendicular on one end of the pushrod. To maintain correct pushrod length, cut the length of the threads the same thickness of the nut.
  4. Install the nut on the rod. The nut is threaded onto the pushrod and jammed where the threads end. And if you're concerned about the nut coming off the pushrod while in use, well, it'll be impossible for it to come off because for one thing, the nut will be jammed tight against the short threads on the pushrod. And when high strength liquid threadlocker is applied, this will secure the nut even better.
    The minimum length of the Kohler 10-16hp flatheads and 18hp OHV engines points pushrod is 1.500" and the maximum length is 1.600". And the minimum length of the Kohler 7hp and 8hp engines points pushrod is 1.250" and the maximum length is 1.260". As long as it's anywhere between these measurements, it should work fine. If it's too long, the points' contacts won't touch and the rod will need to be shortened. But if the rod is too short, the contacts won't open enough or at all and the rod will need to be replaced with a longer one. So measure accurately before (re)installing! The minimum diameter of each pushrod is .184".
  5. On the 7hp and 8hp Kohler engines, the nut will need to be reduced in diameter (in a small metal lathe), and the inside of the block will need to be ground away for clearance of the nut.
  6. Remember that the pushrod must be inserted from inside the block before the camshaft is reinstalled!
  7. This can also be done for an unworn lobe, to keep it from wearing later.
  8. See image below Ê for a better understanding. Ê

Points Pushrod w/Nut

Grinding of the Point LobeIf doing the above È doesn't help to advance the timing quite far enough (for gas and especially methanol fuel), grinding (and polishing) of the lobe may need to be done. Grind about .050" deep into the surface just before the lobe (see drawing to the right) and about 1/2" from the lobe to right next to the lobe, but not on the lobe itself! A die grinder with a porting stone works excellent for doing this. After doing this, the timing can then be advanced as far as 50º BTDC!

When advancing the ignition timing past 24º± BTDC, and if the camshaft has an automatic compression release, it will need to be removed because the spark will occur when the exhaust valve opens slightly to relieve some of the compression, preventing the engine from starting. And to make the engine easier to crank over and start under full compression, a high torque starter motor with separate starter and ignition switches to prevent "kick back" will need to be used.

By the way - to keep crankcase oil from contaminating the ignition points on a Kohler engine, install a Diaphragm Seal, OEM Kohler part # 220074-S. It slides over the pushrod, and is held in place by the points bracket.

Another (low cost) way to keep crankcase oil from contaminating the ignition points on a Kohler engine is to install a new [hardened steel] points pushrod and/or if the hole in the block is worn, install a small, snug-fitting neoprene rubber o-ring on the points pushrod. Place the o-ring on the outside and close to the engine block. The oil will travel out to the o-ring and drip off, staying off the points. But if the hole for the points pushrod is excessively worn, this will effect the ignition timing as well, and the block will need to be machined for installation of a bronze sleeve bushing. FYI - Bearing bronze is porous, very hard, and lasts a long time when lubricated and used as a bushing. Brass, on the other hand, is soft, non-porous and wears quickly when used as a bushing.


Be Professional With Your Tractor's Wiring!

When connecting the wires for an electrical system, don't just make a connection by twisting the wires together by hand and then taping them up. All this does is allow moisture between the wires and in time, lets corrosion set in, causing a faulty connection. Instead, solder the wires together, then tape them up electrical tape or use heat-shrink wrap of the correct size. Or use "crimp" style wire connectors to connect the wires together or to connect a wire onto a coil, switch or terminal. Route the wiring along the inside of the frame in a safe manner, away from any rotating parts, hot exhaust areas and for a "clean" and professional look.

And if using an automotive automatic-reset circuit breaker in a garden pulling tractor, don't fasten it to anything solid, such as the steering column or any metal part of the tractor. Instead, allow it to dangle free, but wrap some electrical tape around it so the terminals won't short out against any bare metal part of the tractor. The reason the circuit breaker shouldn't be mounted solid is because at high rpms or at wide open throttle, normal engine vibrations will momentarily cause the bimetallic strip (contact spring or "flapper") inside the breaker to vibrate (a lot) and become momentarily disconnected, causing the engine to run erratically, misfire badly or "cut out" while going down the track. Or better yet, instead of using a circuit breaker, install either an in-line fuse holder or in-dash (pedestal) fuse holder.


Ignition System Options - Top of page

If a Kohler K-series engine originally came with points and condenser ignition, and you're looking for a more reliable and maintenance-free ignition system, well, you have these options...

If a Kohler K-series engine originally came with breakerless ignition and the Breakerless Trigger Unit quit functioning, and installing a new one is cost-prohibitive (Kohler part # A-237339, $205.00 retail as of 2013), and you're looking for a lower-cost alternative ignition system, well, you have these options...

If the solid state ignition on a Kohler Magnum engine quit functioning, and you're looking for an alternative ignition system, well, you have these options...


Crank Trigger Electronic Ignition Section - Top of page

Okay, so you've got a fancy carburetor or fuel injection system, custom-machined billet cylinder head, bigger valves, a quality-ground high performance camshaft, forged piston, billet connecting rod, steel crankshaft, etc., but you're still running the old-fashioned points and condenser ignition system? Use the latest state-of-art technology! Upgrade to Crank Trigger Electronic Ignition for reliability, durability and to be truly competitive on the track!

NEW & IMPROVED BRIAN MILLER CRANK TRIGGER ELECTRONIC IGNITION SYSTEM COMING SOON!
Please check back for updates.

This is the era of modern wonders, where everything is transistorized, digitized and miniaturized. Yet even today, many garden tractor pullers still use breaker point ignitions on their garden pulling tractors. For other people, the frustration of attempting to keep a breaker point-fired tractor in peak running condition has been enough of a reason to join the electronic era. Breaker point systems do have some positives, though. Points are cheap and somewhat easy to install. And many pullers are comfortable with setting-up their points. But for the utmost precision ignition timing and maintenance-free convenience, crank trigger electronic ignition is the way to go! It will allow the engine to idle better, run smoother, and produce more power at high rpms or at wide open throttle.

Tired of changing or constantly adjusting the ignition points? Convert to the 100% digitized crank trigger electronic ignition! For improved performance, easier starting, and less moving parts to leave your tractor dead on the track. Shock and moisture resistant, and all it takes is a few simple hand tools to install. In my opinion, getting rid of the points and condenser has been the best advance ever in engine technology.

Virtually Any Engine Can Be Converted To Crank Trigger Ignition!

If an engine is connected to a battery (and if it has a charging system to keep the battery fully charged for prolong use), and if there's room on the PTO end of the crankshaft for the trigger disc, and a place to mount the bracket for the magnetic pickup coil or inductive proximity sensor, then the engine can be converted to crank trigger ignition. And the trigger disc doesn't have to be made of aluminum. If there's a steel hub mounted on the end of the crankshaft, it could be used to trigger the ignition. As long as the head(s) of the trigger screw(s) is/are higher than the circumference of the [steel] hub, the magnetic pickup coil or inductive proximity sensor will detect it/them.

Stable ignition timing is a necessity in high performance engines. In most cases, a points ignition will do just fine, but when you start making big time horsepower with extreme cylinder pressures and higher rpm, the timing is critical to both the performance and life of the engine. The ignition must be triggered at a precise time in relation to the position of the piston during the compression stroke. However, the timing can get erratic or fluctuate at high rpms or at wide open throttle with the points system, due to camshaft end play, clearance in both the crank and cam gears and mechanical flexing that takes place through the camshaft support pin, especially when using a high lift cam with very stiff valve springs. In fact, if you ever checked the timing on an engine with camshaft-operated points using an inductive strobe timing light, you may have noticed that the timing marks will fluctuate or "jump up and down" a few degrees. And it'll fluctuate more as the engine rpms increases. This won't happen with crank trigger ignition. It totally eliminates spark scatter or fluctuations and erratic timing problems common with point ignitions. With crank trigger ignition, the "tighter" the main bearings are, the more stable the timing is.

When checking the timing with an inductive strobe timing light on an engine with crank trigger and main ball bearings, it's best to run the engine until it reaches normal operating temperature. The reason for this is the free play in the ball bearings is lessened as the bearings get warm, providing a more stable spark.

The crankshaft knows exactly where the piston is, plus it is the most stable component in an engine in relation to piston position. That's why a crank trigger ignition is so important in high-horsepower/high rpms or at wide open throttle engine applications. With this ignition, you get absolutely stable timing with ± 1/10th of a degree of accuracy from 0 to 15,000+ rpms without missing a beat (when using an electronic ignition control module with a high capacity transistor). The ± 1/10th of a degree is the result of the clearances in the main bearings. With an electronic ignition control module with a high capacity transistor, the crank trigger ignition system will work flawlessly without missing a hit even if an engine can turn up to 100,000 rpm! Because it works as fast as electricity can travel. As long as it's installed and adjusted correctly, it'll help an engine scream down the track. Also, with the crank trigger ignition system, you can set the ignition timing and forget it!

Crank trigger ignition is when the mechanical breaker points and condenser are totally eliminated and replaced by solid state transistorized circuitry. Actually, it works on the same principle as the electronic ignition that's used in the older automobiles (before computerized ignition systems). The conventional points ignition system is considered as old-fashioned technology by today's standards. Even the [high dollar] aftermarket adjustable ignition plate that's made for Chevy points is considered old-fashioned by today's standards!

Using points versus crank trigger is up to you. Personally, I prefer the crank trigger setup because it's very reliable and virtually maintenance free. With conventional ignition, the points will ALWAYS go bad or wear out. The contacts on points can get dirty, worn, burnt, oily (oil seepage from the crankcase), out of adjustment, wet (whenever the tractor is washed off or rained upon) or even oxidized (light corrosion). The use of a high-output/performance ignition coil can also shorten the life of points. And the condenser can go bad. Because all high-output/performance ignition coils draws more amps from the battery, if they are not used with a ballast resistor, they will likely burn a good set of ignition points in a short time. All high-output/performance ignition coils also require two ordinary, standard capacity condensers or one high capacity/performance condenser so it can produce full voltage. But high-output/performance ignition coils have no effect whatsoever on the GM, Chrysler or Ford electronic ignition control module (ECU), even if two automotive-type canister coils, a 2-post Harley-Davidson coil (this particular coil also fits Kohler engine models K482, K532, K582, K660 and K662), or a GM DIS coil is used! (Chevy 2 post coil; DIS stands for Distributorless Ignition Systems.) The DIS coil part numbers are AC Delco D555 or Standard Motor Products DR39X, and was used in select GM vehicles from 1985 to the 2005, one of which is the 2005 Chevrolet Impala. There's no certain way to connect the wires to the primary windings in the GM DIS coil. There is no positive (+) or negative (-) side. Just connect the wires to either terminal. The DIS coil is a high-output/performance coil, which means the spark plug gaps can be set at .060" each. When using points with 12 volts, install a ballast resistor to prevent burning up the coil, and connect two ordinary, standard capacity condensers or one high capacity/performance condenser so the oil will produce full voltage. A ballast resistor is not required with a 6 volt system. And crank trigger ignition is much safer than points. Because ignition point contacts creates a spark (which is normal), there's always danger of a fire if there's ever a fuel leak. The only spark that occurs with crank trigger ignition is at the spark plug's tip.

Go here to see how well the GM DIS coil works: Gravely 817 Onan CCKA Coil Replacement with Chevy GM DIS Coil - YouTube (Video posted by Ralph @ rw3dog@yahoo.com)

At very high rpms or at wide open throttle, with conventional points and condenser ignition, the ignition coil operates at about 80% efficiency. The same is true with high-output/performance ignition coils because they require more amps. But with crank trigger ignition using the Chrysler or Ford electronic ignition control module, any type of coil operates at 100% efficiency at any rpm, which produces a much hotter spark. This is why General Motors refers to their 1974-'86 electronic ignition as HEI, or High Energy Ignition. The reason there's a hotter spark is because at higher rpm, there's no condenser to break down the voltage in the primary circuit in the coil.

When a magnetic pickup coil is used with crank trigger ignition, the duration of each spark lasts about twice as long than with points and condenser ignition. And when an inductive proximity sensor is used with crank trigger ignition, the spark duration is about 4 times longer than with points and condenser ignition, because an inductive proximity sensor can detect the trigger screw at the farther distance than a magnetic pickup coil. A longer spark duration burns the fuel more thoroughly, especially at very high rpm, resulting in more power. Although an inductive proximity sensor can be used on a stock engine running at around 4,000 rpms with no problems, it's more suited for a high performance engine (than the magnetic pickup coil) due to its longer spark duration. In other words, a stock engine with limited rpms will not benefit from the longer spark duration. Also, the closer the magnetic pickup coil or inductive proximity sensor is set to the trigger screw, the longer the duration will be.


Items needed and details on how to install a Crank Trigger Electronic Ignition System (on virtually any engine) are listed below Ê Top of page

ü A Universal Magnetic Pickup Coil, Crankshaft Position Sensor, Tach/Speed Sensor or an Inductive Proximity Sensor. Virtually any automotive engine speed sensor or crank position sensor will work for this system. These all work the same. These sensors require no power from the battery or module because they self-generate an AC signal. Be sure to use a magnetic one that produces a small electrical current whenever a small steel (nonmagnetic) object is passed quickly over the end of it. Also, there needs to be a way to mount it on the engine so the air gap and ignition timing can be set and/or adjusted. A universal magnetic pickup coil is most common for this application. It's an engine speed sensor (Tach Sensor) that threads into the bellhousing of a late model truck with a Diesel engine for activation of the tachometer. A crank position sensor is an automotive unit that threads into the engine block and reads off a cogged wheel mounted on the crankshaft. It's for a crank trigger ignition system that's on an automobile with a computer-controlled engine that has electronic fuel injection.

Some GM crank position sensors have three or more wires, but are activated by just two wires. The third (or other) wire(s) is ground or neutral and really doesn't need to be used with crank trigger ignition. When you buy a sensor, test it to see which wires produce the electrical current, then just snip off the other wire(s). And a used sensor can be easily tested by connecting it to a digital or analog voltmeter that's set on the lowest AC scale and then quickly pass the head of a small steel bolt or nail back and forth across the end of the sensor. If the digital type fluctuates or analog needle bounces slightly each time the metal object makes a pass, the sensor is good. Also, the more voltage a sensor produces, the hotter the spark. I sell 3/8" diameter universal magnetic pickup coils further down in this website.


ü A High Performance GM (Chevy) HEI 4-Pin Ignition Control Module can be used for the crank trigger ignition system. The high performance GM modules will allow an engine to accelerate at high rpms or run at wide open throttle because they have a larger and high capacity transistor to handle the reaction time of increased input or pulses from the ignition coil. The high performance HEI module to use for crank trigger ignition are either: ACCEL # 35361, Pertronix Flame-Thrower # D2070, Dyna-Mod Module 4 Pin # DUI 222, Proform # 66944C, Allstar # 81208, Moroso # 97857, and there's a few others available. If a stock or standard-output/ordinary GM 4-pin module is used, the engine will idle fine, but may not accelerate. The HEI module is also vibration-proof because it has an electronic circuit board, meaning there's no internal loose wires to vibrate and break due to normal engine vibration. Slip-on crimp-type female spade wire connectors can be used on the terminals of the module. Ground the module through the two mounting holes so it will work. This type of ignition module is designed for 1975-84 General Motors vehicles (Chevrolet, Pontiac, Oldsmobile, Buick, Cadillac and GMC truck) with an L4, L6, V6 or V8 engine, but being it's small and compact, it's ideal for use on a garden pulling tractor or small engine with limited space. And this is not a spark advance module. The ignition timing stays constant at all times with this module. Which means it doesn't advance or retard the timing at any rpm.


ü A Chrysler, Dodge or Plymouth (MOPAR) Electronic Ignition Control Module (ECU) can also be used for crank trigger ignition. The OEM standard-output/ordinary Chrysler module works great on a garden pulling tractor for durability and all-out performance. Plus it's vibration-proof because the internal electronic components are sealed in epoxy. This means there's no internal wires to vibrate and break due to normal engine vibration. And being a new Chrysler electronic ignition control module wiring harness cost about $20.00-$45.00, I recommend getting the connector w/wire leads off a 1972-1992 Chrysler, Dodge or Plymouth vehicle that's in a salvage yard. But if you want to get a new one, the part number is Standard S-516. But if an OEM wire connector/plug isn't available, slip-on, crimp-type female bullet wire connectors can be used on the terminals of the module and held in place with Clear RTV Silicone Adhesive Sealant. Ground the module with the mounting base holes so it will work. This type of module was used from 1972 through 1992, except on vehicles with the "lean burn" ignition. Also, tests has proven that an OEM/stock Chrysler module performs just as well as an aftermarket high performance [Mopar] modules when used on a garden pulling tractor. And this is not a spark advance module. The ignition timing stays constant at all times with this module. Which means it doesn't advance or retard the timing at any rpm. For accurate and detailed wiring information and diagrams, please click here or scroll down further in this web page. I offer this module for sale further down in this website.

The electronic ignition control module, inductive proximity sensor or magnetic pickup coil could burn up (possibly instantly) if the wires aren't connected to the right terminals! When connecting the wires, take your time and make sure to use different colored wires to avoid confusion. And be sure to fasten all wiring securely to avoid breakage or loose connections from normal engine or tractor vibration. And when mounting the Chrysler module, mount it away from excessive heat and remember that the exposed power transistor is electrically hot while the power is on. The unit should be mounted in an area which minimizes the possibility of shorting the transistor when working in the engine area. Shorting the power transistor to the heat sink or any ground could damage the unit.

Virtually any automotive parts supply store carries the stock type Chrysler electronic ignition control module. They retail for about $21.00 and up. Various manufacturer's part numbers are: EL110 (G.P. SORENSEN, available at Advance Auto Parts stores); MPETP50SB (NAPA); LX101 (STANDARD); CBE14 (Borg-Warner); AL403 (NIEH); TP51 (ECHLIN, available at NAPA Auto Parts stores); CH301 (FILK); CR109 (WELLS); E106 (KEM); C1900Z (AC DELCO) and AL-401 (NIEHOFF IGNITION). Or just tell the counter person it's for a 1972 Chrysler Imperial.

ü A Ballast Resister or a Full-Length Resistance Ignition Wire is required with the Chrysler module!
The Chrysler electronic ignition control module (off any 1972-85 Chrysler, Dodge or Plymouth vehicle), whether if it's a stock or a high performance one, require a ballast resistor (off any 1955-57 GM vehicle) or a full-length resistance ignition wire (off any 1958-74 GM vehicle) to prevent putting too much voltage into it and burning it up. It's best to use at least a 1.2 ohm ballast resistor for the Chrysler electronic ignition control module. Anything less, and the module could burn up. A ballast resistor or resistor wire is basically a voltage reducer that reduces 12 volts down to between 6-9 volts, depending on the load. (The ballast resistor shown here is the same used on the 1955-57 GM vehicles.) The reason the Chrysler module doesn't have a built-in resistor is because as the resistor heats up while the module is in operation, the heat from the resistor could travel to and damage other sensitive internal electronic components within the module. I also offer this ballast resistor for sale further down in this website.


ü Another type of electronic ignition control module that works great for crank trigger ignition is one that's made for certain domestic Ford, Lincoln and Mercury vehicles. This type of unit operates off of full 12 volts, which means it does not require a ballast resistor. It's also high performance when used on a small engine or garden pulling tractor. And just like the Chrysler module above, this one is also vibration-proof because the internal electronic components are sealed in epoxy. This means there's no internal wires to vibrate and break due to normal engine vibration. The correct module to use has a blue grommet and comes with its own wiring harness. The OEM connectors/plugs can be snipped off and crimp-type connectors installed when used on a small engine or garden pulling tractor. Ground the module with the mounting base holes so it will work. And this is not a spark advance module. The ignition timing stays constant at all times with this module. Which means it doesn't advance or retard the timing at any rpm. I offer this module for sale further down in this website.

Here's a list of Ford and Motorcraft part numbers for the Ford blue grommet electronic ignition control module:
Auto Parts Stores Cross Reference -
FF402 (NIEHOFF); MF-481 (Mitech); F0306 (Filko); F102 (AmpcoWells); E302 (Kem); EL107M (G.P. SORENSEN, available at Advance Auto Parts stores); LX203 (STANDARD); F1910 (AC DELCO), ECHTP36 or ECHTP40 (ECHLIN, available at NAPA auto parts stores); F100 (Duralast).

Ford -
D6AB-12A199-A1B, A2B; D6AE-12A199-A1A, A1B, A2A, A2B, AA; D6AZ-12A199-A, B; D6TE-12A199-A1A D6TZ-12A-199-A; D7AZ-12A199-B; D8AE-12A199-A1E; D8VE-12A199-A1A, A1B, A1C, A2A, A2B, A2C; D9VZ-12A199-A; E1FZ-12A199-A; E8PF-12A199-AA, AB; E9VZ-12A199-A; F2PF-12A199-AA; F2PZ-12A199-AA.

Motorcraft -
DY-184, A, B, C; DY-198, DY337, DY-611, DY-683, DY-893.

Donor Vehicles -
American Motors: AMX 78-80; Concord 78-81,83; Eagle 80-81, 83-87; Gremlin 77-78; Hornet 77; Matador 77-78; Pacer 77-80; Spirit 79-81,83.
Ford: Bronco 76-87; Custom 75-77; E Van 89-89,95; Elite 75-76; Escort 81-82; EXP 82; F Pickup 76-87,97; Fairmont 78-83; Fiesta 78-80; Gran Torino 75-76; Granada 75-82; LTD 75-86; LTD II 77-79; Maverick 76-77; Mustang 79-85; Mustang II 76-78; P Series 76-77; Pinto 76-80; Ranchero 76-79; Ranger 83-88; Tempo 84-87; Thunderbird 75-83; Torino 75-76.
Jeep: Cherokee 77-85; CJ5 77-83; CJ7 77-86; Grand Wagoneer 84-87; J Series 77-87; Scrambler 81-85; Wagoneer 77-85.
Lincoln: Continental 76-80, 83-85; Mark IV 76; Mark V 77-79; Mark VI 80,82-83; Town Car 82-83; Versailles 77-80.
Mercury: Bobcat 76-80; Capri 77-76,79-86; Comet 76-77; Cougar 76-84; Grand Marquis 76-83; LN7 82; Lynx 81-82; Marquis 76-85; Monarch 76-80; Montego 76; Topaz 84-87; Zephyr 78-83.

The electronic ignition control module, inductive proximity sensor or magnetic pickup coil could burn up (possibly instantly) if the wires aren't connected to the right terminals! When connecting the wires, take your time and make sure to use different colored wires to avoid confusion. And be sure to fasten all wiring securely to avoid breakage or loose connections from normal engine or tractor vibration.


NOTE: Not all automotive electronic ignition control modules will work adequately for the crank trigger ignition system! Because some modules have a small transistor, which can't react quick enough to the increased rpms when triggered directly off the crankshaft. They're made to operate off the magnetic pickup coil that's positioned inside the distributor in an automotive engine that rotates half the speed of the crankshaft, which fires every other revolution per piston travel. So when choosing a module, make sure that it can handle increased rpm, at least up to 4,000 rpms (for a stock engine) and 15,000 rpms for a fully modified engine. And for stable ignition timing, the triggering device must operate directly off the crankshaft. And although the MSD control box will work excellent for the crank trigger ignition, it's not a good thing to use it on a garden pulling tractor because the wires inside the box have been known to break due to normal engine/tractor vibration. When using any type of module, make sure the internal wires and components are epoxy sealed to prevent vibration and breakage. If you have doubts that an electronic ignition control module is defective, you can have it tested (usually free of charge) at virtually any auto parts store.


The only reason any engine would need the ignition timing retarded or a spark advance system is so the engine won't "kick back" when attempting to start it. "Kick back" occurs when the flywheel/crankshaft suddenly and violently rebounds or momentarily rotates in the opposite direction, which is could bend or break the starter armature shaft or the aluminum starter housing. Virtually all small gas engines nowadays have a compression relief mechanism on the camshaft (that opens the exhaust valve slightly halfway on the compression stroke), which allows the engine to crank over easily without kicking back. And most pulling engines have a long duration camshaft with the compression relief mechanism (if using a cast cam) and a heavier-than-stock [steel] flywheel. Which will also allow an engine to crank over easily without kicking back when starting. So you see, a spark advance really isn't necessary.


Set the air gap (clearance) between the magnetic pickup coil or inductive proximity sensor and trigger screw (in the disc below Ê) at a minimum of .025" and no more than .25" (1/4") with a brass, plastic or paper (anything non-magnetic) feeler gauge. If the gap is wider than .25", the engine could misfire at high rpms or at wide open throttle due to normal engine vibration. And of course, direct metal contact will damage either unit. If the gap is closer than .025", due to normal engine vibration, the magnetic pickup coil or inductive proximity sensor could strike the trigger screw (or disc) and damage could occur, rendering either one useless.


Wiring diagrams for a Magnetic Pickup Coil (Scroll down for the Inductive Proximity Sensor wiring diagrams.)
NOTE: Magnetic Pickup Coils are magnetic, self generating (requires no outside power) and functions with two wires: black and white.
GM HEI ignition control module wiring connections for an ignition coil that does NOT require a ballast resistor:
  • [W] and [G] connects to magnetic pickup coil. It doesn't matter which terminal connects to which wire, being the pickup produces AC voltage.
  • [C] connects to negative (-) terminal on ignition coil.
  • [B] connects to positive (+) terminal on ignition coil, then to 12 volt power source.
  • Module must be grounded through mounting holes so it will work.

GM HEI ignition control module wiring connections for an ignition coil that does NOT require a ballast resistor:
  • [W] and [G] connects to magnetic pickup coil. It doesn't matter which terminal connects to which wire, being the pickup produces AC voltage.
  • [C] connects to negative (-) terminal on ignition coil.
  • [B] connects to positive (+) terminal on ignition coil, and then to 12 volt power source.
  • Module must be grounded through mounting holes so it will work.

Chrysler ignition control module wiring connections for an ignition coil that does NOT require a ballast resistor:
  • [A] and [B] connects to magnetic pickup coil. It doesn't matter which terminal connects to which, being the pickup produces AC voltage.
  • [C] connects to ballast resistor, then to positive (+) terminal on ignition coil, then to 12 volt power source.
  • [D] connects to negative (-) terminal on ignition coil.
  • Frame of module must be grounded, so it will work.

Chrysler ignition control module wiring connections for an ignition coil that DOES require a ballast resistor:
  • [A] and [B] connects to magnetic pickup coil. It doesn't matter which terminal connects to which wire, being the pickup produces AC voltage.
  • [C] connects to ballast resistor, which connects to positive (+) terminal on ignition coil, then to 12 volt power source.
  • [D] connects to negative (-) terminal on ignition coil.
  • Frame of module connects to chassis ground, so it will work.

Ford ignition control module wiring connections for an ignition coil that does NOT require a ballast resistor:
  • Orange and Purple connects to magnetic pickup coil. It doesn't matter which wire connects to which wire, being the pickup produces AC voltage.
  • Red connects to positive (+) terminal on ignition coil, then to 12 volt power source.
  • Green connects to negative (-) terminal on ignition coil.
  • Black connects to chassis ground, so module will work.
  • White is for timing retardation only and not used in this application.

Ford ignition control module wiring connections for an ignition coil that DOES require a ballast resistor:
  • Orange and Purple connects to magnetic pickup coil. It doesn't matter which wire connects to which wire, being pickup produces AC voltage.
  • Red connects to directly to 12 volt power source, then to ballast resistor, which connects to positive (+) terminal on ignition coil.
  • Green connects to negative (-) terminal on ignition coil.
  • Black connects to chassis ground, so module will work.
  • White is for timing retardation only and not used in this application.

Ignition Wiring Diagrams for a Normally Open (NPN) Inductive Proximity Sensor -
FYI - Inductive Proximity Sensors requires external power and functions with three wires: blue, brown and black. They come in two versions: Normally Open (NPN) and Normally Closed (PNP). On models equipped, the LED sensor will illuminate when energized. A Normally Open sensor produces electrical current to the ignition module only when it comes in close proximity of a detectable ferrous metal (steel) object, then the circuit is closed (LED sensor comes on). Normally Open sensors are used mainly for crank trigger ignition systems on gas engines. A magnetic pickup coil works like a Normally Open (NPN) sensor. Inductive proximity sensors also work almost like metal detectors; if the metal comes close enough to the sensor, an alarm will sound. But a Normally Closed sensor produces electrical current to the module at all times (LED sensor goes off) while external power is supplied to it except when it comes in close proximity of a detectable ferrous metal object, then the circuit is opened (LED sensor comes on). Normally Closed sensors are used mainly in places where security is needed. They can be used for exterior windows or doors in a building. When a window or door with a detectable ferrous metal object is moved away from the sensor, the circuit will be closed and an alarm will sound and/or lights will come on. If an inductive proximity sensor has no markings or indications to show that it's a PNP or NPN, a 100% sure way to determine the type, is to test it with wires connected in a circuit (as shown below Ê), bring a steel object close to it, then observe for spark at the spark plug's tip. NOTE: If a Normally Closed Inductive Proximity Sensor is wired incorrectly, the LED sensor will stay ON and go OFF when activated. (Normally Open sensors will work as Normally Open.)

GM HEI ignition control module wiring connections for an ignition coil that does NOT require a ballast resistor.
  • [W] connects to Black wire on sensor. But sometimes [G] connects to the Black wire.
  • [G] connects to Blue wire on sensor and chassis ground (negative (-) battery). But sometimes [W] connects to Blue wire and chassis ground.
  • [B] connects to Brown wire on sensor and positive (+) terminal on ignition coil, then to 12 volt power source.
  • [C] connects to negative (-) terminal on ignition coil.
  • Module must be grounded through mounting holes so it will work.

GM HEI ignition control module wiring connections for an ignition coil that does NOT require a ballast resistor:
  • [W] connects to Black wire on sensor. But sometimes [G] connects to Black wire.
  • [G] connects to Blue wire on sensor and chassis ground (negative (-) battery). But sometimes [W] connects to Blue wire and chassis ground.
  • [B] connects to Brown wire on sensor and positive (+) terminal on ignition coil, then to 12 volt power source.
  • [C] connects to negative (-) terminal on ignition coil.
  • Module must be grounded through mounting holes so it will work.

Chrysler ignition control module wiring connections for an ignition coil that does NOT require a ballast resistor:
  • [A] connects to Blue wire on sensor and chassis ground (negative (-) battery).
  • [B] connects to Black wire on sensor.
  • [C] connects to Brown wire on sensor, to ballast resistor, then to positive (+) terminal on ignition coil, then to 12 volt power source.
  • [D] connects to the (-) negative terminal on the ignition coil.
  • Frame of module must be grounded, so it will work.

Chrysler ignition control module wiring connections for an ignition coil that DOES require a ballast resistor:
  • [A] connects to Blue wire on sensor and chassis ground (negative (-) battery).
  • [B] connects to Black wire on sensor.
  • [C] connects to Brown wire on sensor, to positive (+) terminal on ignition coil, then coil connects to ballast resistor, and to the 12 volt power source.
  • [D] connects to the negative (-) terminal on the ignition coil.
  • The frame of the module connects to chassis ground, so it will work.

Ford ignition control module wiring connections for an ignition coil that does NOT require a ballast resistor:
  • Orange or Purple connects to Black wire on sensor. (If one wire doesn't work, then try the other.)
  • Orange or Purple connects to Blue wire on sensor (if one wire doesn't work, then try the other) and to chassis ground (negative (-) battery).
  • Red connects to Brown wire on module, and to positive (+) terminal on ignition coil, then to 12 volt power source.
  • Green connects to negative (-) terminal on ignition coil.
  • Black connects to chassis ground, so module will work.
  • White is for timing retardation only and not used in this application.

Ford ignition control module wiring connections for an ignition coil that DOES require a ballast resistor:
  • Orange or Purple connects to Black wire on sensor. (If one wire doesn't work, then try the other.)
  • Orange or Purple connects to Blue wire on sensor. (If one wire doesn't work, then try the other) and to chassis ground.
  • Red connects to ballast resistor, and then to positive (+) terminal on ignition coil.
  • Green connects to negative (-) terminal on ignition coil.
  • White connects to Brown wire on sensor and 12 volt power source.
  • Black connects to chassis ground, so module will work.

Crank trigger ignition will work on virtually any single or multiple cylinder gas engine.

Degree Increments for a Super Spacer or Rotary Table with a Self-Centering 3-Jaw Chuck -
This chart is for installing multiple trigger screws in the trigger disc for the crank trigger ignition. It also comes in handy for drilling 5 holes in axle flanges and other things.
NOTE: The degrees shown is not for the spark to occur at 0º TDC for each cylinder. They are so each cylinder will have equal timing or distance of spark between them.

Number of holes to be drilled - 1st 2nd 3rd 4th 5th 6th 7th 8th 9th
For a 2 cylinder engine or 2 holes 180º
For a 3 cylinder engine or 3 holes 120º 240º
For a 4 cylinder engine or 4 holes 90º 180º 270º
For 5 holes 72º 144º 216º 288º
For a 6 cylinder engine or 6 holes 60º 120º 180º 240º 300º
For an 8 cylinder engine or 8 holes 45º 90º 135º 180º 225º 270º 315º
For 9 holes 40º 80º 120º 160º 200º 240º 280º 320º

Crank Trigger will spark on the compression stroke for each piston when used on a multiple cylinder engine. It'll also work excellent on any 2-cycle engine, because it fires on every stroke of the piston. On a twin or two cylinder engine, use just one Chrysler or Ford electronic ignition control module, one magnetic pickup coil or inductive proximity sensor, one trigger screw in the trigger disc located at approximately 20º BTDC on the compression for the #1 cylinder. It'll spark for the #2 cylinder at 20º BTDC on the compression stroke, too. And you could install two standard-output/ordinary automotive ignition coils, one for each cylinder. Wire them together as you would for one coil. As the trigger screw passes the pickup coil, a spark will be produced for each cylinder, one piston being on the compression stroke and the other on the exhaust stroke and vice-versa. It'll work identically the same as Briggs & Stratton's Magnetron™ ignition on their twin cylinder flathead (valves in block) engines. Because the flathead Briggs twins use a single ignition coil. By the way, the stock timing on Briggs engines for gas is set at 11º BTDC. Special-made offset flywheel keys for Briggs & Stratton engines.To advance the timing for methanol fuel, a special-made offset flywheel key must be used. They come in 2º, 4º, 6º and 8º increments. Use the 6º one for a setting of 17º BTDC. The offset flywheel keys are used mostly in racing go-karts and Junior Dragsters.

For a Kohler Magnum or any other make of engine with fixed solid state ignition, to advance the ignition timing when burning either E-85 or methanol fuel, either an offset flywheel key will need to be installed, or a new keyway will need to be broached in the flywheel taper a several degrees advanced from the original keyway. Precise calculation will need to be made to determine the amount of offset in the key, or where the new keyway should be. If cutting a new keyway, the original keyway will need to be filled-in with either bronze brazing or steel stock the same width as the keyway silver-soldered in place to prevent the metal from breaking next to the original keyway when broaching the new keyway slot.

For crank trigger to work on a V-twin small gas engine (B&S Vanguard, Honda, Kawasaki, Kohler Command, etc.), one magnetic pickup coil will need to be used per cylinder and use one control module with dual coils or a GM DIS coil. Position each pickup coil in place where the original ignition coils. And because of the magnet in the flywheel, a different [steel] flywheel will need to used, or replace the magnet with a piece of secured steel weighing the same as the magnet or have the flywheel rebalanced. Then install one trigger screw in the flywheel where the magnet was so the ignition will be in time with each magnetic pickup coil.


If installed correctly, nothing could possibly go wrong with the crank trigger ignition system. Mainly because everything is totally sealed. There's no moving parts to wear and it could very well outlast the life of a typical tractor, even when used in high performance conditions! It's virtually maintenance free, extremely reliable. That's why auto manufacturers, virtually all small engine manufacturers (Kohler's Magnum engines ignition system operates much like crank trigger ignition) and most high performance/racing vehicles nowadays use electronic [or better yet, computerized] ignition. Plus it's something fancy to show off. It's powered by full 12 volts and features a more stable spark than the convention point ignition. You can also use your existing standard ignition coil. And remember, a high-output/performance ignition coil will draw more amps from the battery.

Crank trigger ignition will work on virtually any small engine, but only if there's room on the crankshaft (preferably the PTO end, which is opposite the flywheel end) for mounting of the rotating disc that contains the trigger screw (see below Ê). The trigger screw(s) can also be installed in the factory flywheel. Be sure to allow the head of [each] screw extend approximately 1/8" above the circumference of the flywheel to prevent false triggering. And when mounting the magnetic pickup coil or inductive proximity sensor, make sure it's mounted rigid and stable to prevent erratic timing fluctuations.

On a single cylinder engine, this type of ignition will produce a spark on both the compression and exhaust strokes, which is harmless. Camshaft driven point ignitions only spark during the compression stroke. By the way, Kohler engine is mentioned here only as an example, because they're most common in garden tractor pulling.

The crank trigger ignition system is nothing to be afraid of. Once you understand how it works, it's actually quite simple and you'd feel more confident using it. Also, once you've tried this type of ignition, you'd be reluctant to go back to points. If the crank trigger is installed correctly on an engine and the timing is set right, it'll bring a pulling tractor to life and help it scream down the track! But if an engine already have a factory-installed solid state ignition that is triggered off the flywheel, you really don't need crank trigger ignition. Factory-installed flywheel-triggered electronic ignitions are very stable, reliable and they produce a strong spark. But if you're installing a machined steel flywheel with no trigger magnets or pins on an engine that originally came with solid state ignition and/or there's no provisions (no threaded bolt holes present) on the block to install points, you will need the crank trigger ignition system.


Degreeing the Trigger Disc -

To simplify degreeing the trigger disc, after finding true 0° TDC on the disc, use a 6" protractor to make timing degree marks on the disc. Refer to the animated drawing to the right for identification. Hold the protractor on the disc, align the 0° TDC mark on the disc with the zero on the protractor and then, facing the disc as if it were mounted on the PTO end of the engine, and with the magnetic pickup coil or inductive proximity sensor mounted either above the disc or on the side of the engine block, make the marks on the disc going counterclockwise of the TDC mark. Going counterclockwise of the 0° TDC mark would be advancing the ignition timing, and clockwise of the 0° TDC mark would be retarding it. Degree it as shown in the drawing to the left. But make sure that the marks on the disc are according to how the disc is going to be mounted on the crankshaft, with the center protruding hub facing toward the engine or away from it. Otherwise, the marks could be on the wrong side of the disc. (Most of the time, the protruding part of the hub faces away from the engine.)

The trigger disc doesn't have to be made of aluminum. If there's a steel hub or disc mounted on the end of the crankshaft, it could be used to trigger the ignition. As long as the head(s) of the trigger screw(s) is/are higher than the circumference of the [steel] hub, the magnetic pickup coil or inductive proximity sensor will detect it/them and not the hub or disc.

NOTE: The trigger screw can be located anywhere in the trigger disc, as long as it's positioned 20° BTDC. Find the true 0° TDC on the disc, then locate the 20° BTDC position from there. On an engine that runs clockwise when facing the front of the engine (flywheel or harmonic balancer), with the disc on the PTO end of the crank, and when facing the PTO end, the 20° position will be counterclockwise from the 0° TDC mark. On flywheel end, the 20° BTDC position is clockwise from 0° TDC.


Set the ignition timing according to piston travel in the cylinder, as mentioned earlier in this web page. Install a timing degree indicator mark (with a felt marker) on the disc and a mark on the engine block and then make a final check of the ignition timing with engine running using an inductive strobe timing light.


How It Works:

The magnetic pickup coil or inductive proximity sensor is able to detect the presence of the trigger screw object without any physical contact. Each time the trigger screw in the rotating disc pass the magnetic pickup coil or inductive proximity sensor, this generates a small electrical current within the pickup coil or sensor. This current is sent in the form of a signal to the electronic ignition control module; within, a transistor opens the primary circuit in the ignition coil and the spark occurs. All this happens at the speed of electricity, which is 95 to 97% that of the speed of light. The conventional ignition points and condenser ignition system is much less responsive.

Checking for Spark -

Because this system produces a spark at very low cranking speeds, once installed, you can check for spark simply by rotating the crankshaft (rotating disc) back and forth by hand so the steel trigger screw passes the magnetic pickup coil or inductive proximity sensor. But turn the ignition switch on first. Also, after the engine has been ran, and because there may be some raw fuel remaining in the combustion chamber, crank trigger ignition will produce a spark once each time the ignition switch is turned on. Sometimes this single spark will make an engine go "poof!" which is harmless in most cases.

To test if an ignition control module is working or not, connect a fully charged 1.5 volt [flashlight] battery to the two terminals on the module (being there's no polarity, it doesn't matter which of the two terminals is connected to the battery) that connects to the magnetic pickup coil or inductive proximity sensor (but disconnect the pickup coil first!) and connect the other terminals/wires on the module as usual. With the battery connected, a continuous spark should result at the spark plug's tip. Don't connect the battery to the magnetic pickup coil! It'll burn it up! This test only proves if the module is working or not. It won't show if it's defective. And don't use an automotive portable battery charger alone to supply the power to check for spark or test a module. If a battery charger is used, the crank trigger system may produce a continuous array of sparks at the spark plug's tip even when the magnetic pickup coil or inductive proximity sensor (or 1.5 volt battery) isn't connected. Therefore, a fully charged 12 volt battery should be used.

By the way - I have not received any complaints from our customers or the readers of this website concerning the crank trigger ignition about their engine(s) running erratic or cutting out at high rpm, unless of course, they installed a defective module.

Advertisement: Return to previous page or paragraph.
If you need any of the items listed below Ê, please contact A-1 Miller's Performance Enterprises | 1501 W. Old Plank Rd. | Columbia, MO 65203-9136 USA | Phone: 1-573-256-0313 (home/shop) | 1-573-881-7229 (cell/text). Please call Monday-Friday (except Holidays), 9am to 5pm, Central time zone. If no answer, please try again later. (When speaking with Brian, please be patient because I stutter.) Fax: 1-573-449-7347. E-mail: pullingtractor@aol.com. Send a message with Yahoo Messenger: | Directions to our shop | Yahoo! Maps, 1501 W. Old Plank Rd., Columbia, MO | 1501 West Old Plank Road, Columbia, MO - Google Maps or Map of 1501 West Old Plank Road, Columbia, MO by MapQuest. Click here for more parts and services. | NOTE: To place an order, please call or send an email with a list and description of the parts or services you need. Because as of right now, we're not set up to accept orders through our web sites online. Due to the rising cost of... everything, prices are subject to change.

COMING SOON: NEW IMPROVED BRIAN MILLER CRANK TRIGGER IGNITION!
Please check back for updates.

Inductive Proximity Sensor. Normally Open / NPN type. Requires 6-36 volts of external power. On models equipped, the LED sensor will illuminate when energized. Durable metal shielded threads with two jam nuts, three wire leads and 10 foot long wires. Dimensions: 15/32" (12mm) diameter x 1-3/8" thread length. Click here for wiring diagrams.
  • $40.00 each, plus shipping & handling.
Magnetic Pickup Coil. Self-generating power. Durable metal shielded threads with two jam nuts, two wire leads and 10 foot long wires. Please specify diameter when ordering. Click here for wiring diagrams.
  • 3/8" diameter x 1" thread length. $60.00 each, plus shipping & handling.
  • 5/8" diameter x 2-1/8" thread length. $60.00 each, plus shipping & handling.

Set the air gap (clearance) between the magnetic pickup coil or inductive proximity sensor and trigger screw (in the disc below Ê) at a minimum of .025" and no more than .25" (1/4") with a brass, plastic or paper (anything non-magnetic) feeler gauge. If the gap is wider than .25", the engine could misfire at high rpms or at wide open throttle due to normal engine vibration. And of course, direct metal contact will damage either unit. If the gap is closer than .025", due to normal engine vibration, the magnetic pickup coil or inductive proximity sensor could strike the trigger screw (or disc) and damage could occur, rendering either one useless.

Ignition Control Modules:

New Chrysler ignition control module. Requires a minimum 1.2 ohm ballast resistor to prevent burning up unit. $22.00 each, plus shipping & handling.

  • 1.6 ohm ballast resistor (for Chrysler module above È). $7.00 each, plus shipping & handling.

New Ford ignition control module. Operates off of full 12 volts, requires no ballast resistor. $28.00 each, plus shipping & handling.


Using Crank Trigger Ignition on a Cast Iron Block Briggs & Stratton or Tecumseh Engine - Top of page
For a specifically designed kit to convert a cast iron block Tecumseh engine for use with crank trigger ignition, contact Ed Stoller at 1-203-746-3800 or Mike Brooks at 1-585-243-7765. Their website is: http://enginesandmagnets.com.
For emission purposes, Briggs & Stratton and Tecumseh has phased out their old cast iron flathead engines to get people to buy their new [EPA-approved] OHV aluminum block engines. Tecumseh also discontinued their solid state electronic ignition module for their cast iron flathead engines several years ago. And magneto points/condenser/coil ignition parts for the old B&S cast iron block engines are getting hard to find and they're very expensive. The cast iron block B&S and Tecumseh engines are well-built and reliable engines, and when their OEM ignition parts quit functioning, the only alternative is to install a crank trigger electronic ignition system.

Crank trigger ignition will work on all cast iron block Briggs & Stratton and Tecumseh engines. And the early models don't have a compression release mechanism built into the camshaft. Instead, they start under full compression. The way Tecumseh engines start is their OEM solid state ignition module has a built-in ignition timing retard that automatically advances as soon as the engine starts. And the B&S engines have an extremely heavy flywheel to prevent "kick back" when attempting to start the engine. "Kick back" occurs when the flywheel/crankshaft suddenly and violently rebounds or momentarily rotates in the opposite direction, which is could bend or break the starter armature shaft or the aluminum starter housing. If crank trigger ignition were installed on either of these engines, the ignition timing would have full spark advance at all times and if the engine has a lot of compression, the flywheel/crankshaft will probably "kick back" every time the engine tries to start.

If the engine "kicks back" too many times, this could bend or break the starter armature shaft, or break the aluminum casing on the starter!

An Easy Way to Start an Engine under Full Compression and with Advanced Ignition Timing with No Automatic Compression Release to Prevent "Kick Back":

With the timing permanently set in the advanced position, two separate electric switches will need to be used - one being a push button to crank the engine (with a gear starter), and the other being an ordinary OFF/ON toggle switch to power the ignition. To make this work, first crank the engine to get it spinning over (if the starter motor is strong enough), choke it, and then flip the ignition (toggle) switch to "put the spark to it." Doing this will allow the engine to start easily every time. Because the momentum or energy stored in the spinning weight of the heavy flywheel makes it impossible for the engine to momentarily kick back against full compression with no [advanced] spark. This starting method is also recommended for pulling engines (with points or crank trigger ignition) having a high performance camshaft with no compression release.

An engine with a fixed advanced and non-adjustable ignition timing uses either a mechanical timing retard, which is manually operated or automatic, an electronically-controlled timing retard, a compression release mechanism on the camshaft or a very small hole drilled in the seat next to the exhaust valve to relieve about half the compression at cranking speed.

If a camshaft doesn't have a compression release, then a .050" "hump" of weld can be placed on the base circle of the exhaust lobe on the camshaft just before the piston reaches TDC to relieve half the compression in the combustion chamber on the compression stroke.

  • If an [older model] engine came with ignition points, the camshaft either have a compression release mechanism, or a mechanical timing retard.
  • If crank trigger is installed on an engine with a camshaft that has a compression release and if it still kicks back upon starting (with the timing advanced), then this means that the compression release mechanism is not working or relieving enough compression. Proper valve adjustment (less valve to lifter clearance) is required to fix the problem, or the compression release mechanism is malfunctioning. If the timing is retarded to reduce the possibility of kickback, then the engine will run sluggish and not produce enough power.

No other ignition system will work on these engines. Also, being crank trigger uses a battery ignition coil, this produces a hotter spark than any solid state or magneto ignition system. By the way - the OEM B&S or Tecumseh coil can't be used with crank trigger ignition. A battery ignition coil must be used instead. And a magnetic pickup coil or inductive proximity sensor with an automotive electronic ignition control module must also be used. A special bracket must also be fabricated for the pickup coil or sensor.

For a specifically designed kit to convert a cast iron block Tecumseh engine for use with crank trigger ignition, contact Ed Stoller at 1-203-746-3800 or Mike Brooks at 1-585-243-7765. Their website is: http://enginesandmagnets.com.


Using a Late Model Automotive Electronic Ignition Distributor on an Older Automotive-Type Engine (Hybrid Ignition System) - Top of page.

Chevy HEI DistributorIf you have an automotive-type gas engine in an old car, truck, farm tractor, forklift, construction equipment, boat motor, etc., with a worn out or troublesome point ignition distributor, and/or parts are no longer available or if you want to upgrade it to the modern, more powerful, trouble- and maintenance-free electronic ignition system, then all the engine will need is a battery-powered, non-computer controlled GM HEI [High Energy Ignition] distributor (with the 4-pin electronic ignition control module) and spark plug wires from a 1975-84 General Motors vehicle (Chevrolet, Pontiac, Oldsmobile, Buick, Cadillac or GMC truck) with an L4, L6, V6 or V8 engine. These type of distributors are considered high performance because they produce a hot spark (about 40,000 volts to the spark plugs) for quicker starts, smooth idle and more engine power, and is ideal for use in other makes of engines because the ignition parts are self-contained; the coil is located in the distributor cap and the ignition control module is located in the distributor itself. And there's only one 12 volt wire to power the HEI distributor. A Chevy V8 HEI distributor is shown to the right. The 4 and 6 cylinder ones are similar.

But if there's not enough room or clearance on an engine for the HEI distributor, a smaller diameter non-computer controlled electronic ignition distributor from a Ford, Mercury or Lincoln, or Chrysler, Plymouth or Dodge (MOPAR) vehicle can be used instead. The Ford or MOPAR electronic ignition control module and ignition coil would need to be mounted elsewhere on the vehicle or equipment. And the spark plug wires that's made for these distributors will be needed. These type of distributors and ignition systems are also considered high performance.

How To Convert It:

  1. Cut off the upper half of the old distributor housing and shaft (discard the upper half). Be sure to cut it close to the distributor head.
  2. Cut off the lower half of the HEI, Ford or MOPAR distributor housing and shaft (discard the lower half). Be sure to cut it far from the distributor head.
  3. Machine and adapt the shafts and housings of the lower part of the old distributor onto the upper half of the modern distributor head, and pin the two shafts together (like for shortened automotive axles). Scroll down for information on how to securely pin two shafts together.
  4. Connect just one 12 volt wire from the ignition switch to the HEI distributor. And for the Ford or MOPAR ignition systems, connect the wiring as shown above È in this website for the ignition control module and ignition coil.
  5. The firing order and ignition timing are set the same as for the old distributor/engine.
  6. It'll probably be a lot of work setting it all up, but it'll be worth it in the long run.

How To Securely "Pin" Two Shafts Together:

  1. Carefully measure each shaft to the length they need to be, then cut each in half.
  2. In a small metal lathe (with a self-centering 3-jaw chuck), in one of the shafts, bore a hole .625" (5/8") deep in the end of the shaft that needs to be joined to the other shaft. The diameter of the hole is to be determined by the outside diameter of the shaft.
  3. In the lathe, and on the other shaft, turn down a stub that's in .750" (3/4") in length. Be sure to machine the stub .003" larger so it'll be a press fit for the shaft with the hole. Bevel the stub so it'll press in straight and easy.
  4. Using a hydraulic press, carefully press the two shafts together, leaving an 1/8" gap for a bead of weld. But first align the shafts so the rotor will point to the # 1 cylinder on the distributor cap when the distributor is installed in the engine.
  5. Thoroughly weld the two shafts together, and grind away any lumps of weld so the shaft will slide in the distributor housing(s) (that has been joined together also) with no problems.


A-1 Miller's Performance Enterprises Offering Quality Products and Professional Workmanship at Reasonable Prices!

à Return to Main Pulling Tips Page | Return To Previous Page | Reputable Garden Pulling Tractor Engine Builders, Parts Suppliers and Service Providers | Miller's Garden Pulling Tractor Picture Gallery | Pulling Sled for Garden Tractors Picture Gallery | Classified Advertisements for Garden Pulling Tractors, Related Parts & Pulling Event Announcements | Hot Links for Various Garden Tractor Pulling Clubs and Associations | Top of Page

© 1996-Present. Designed and maintained by Brian Miller.