Kohler Ignition Coil Problems

Kohler Ignition Coil Problems

You’re all set for a weekend of lawn care, but your Kohler-powered mower refuses to start. Frustrating, right?

You should know that the ignition coil, a crucial component responsible for sparking life into your engine, could be the culprit.

Approximately 50% of small engine failures are ignition-related. In the coming sections, we’ll dive deep into Kohler ignition coil problems — signs, causes, and how to fix them.

This is more than just a mechanical issue; it saves time and averts potential disaster. Trust me, you’ll want to keep reading.

The Role of the Ignition Coil

The ignition coil pumps voltage to your spark plugs. When you turn the ignition key, the coil receives a low-voltage electric spark from the battery.

It then transforms this into the high voltage needed to ignite the fuel-air mixture in the cylinder. In this case, the baton is a jolt of electricity strong enough to kickstart combustion.

Other components, like spark plugs and the distributor, can only perform their roles with the ignition module. The ignition coil ensures that the engine fires up and keeps running.

Understanding the coil’s function is your first step toward diagnosing and fixing potential problems.

Kohler Ignition Coil Problems

Common Signs of Kohler Ignition Coil Problems and Their Causes

1. Poor start

A poor start is often the first symptom that something’s amiss with your Kohler ignition coil. The ignition coil’s role in sending voltage to the spark plugs is vital for successful ignition.

If the coil is faulty, the spark is nonexistent, making it difficult for the engine to start the combustion process.

You grab your trusty Kohler mower to cut the grass. But today, it won’t start. You try and try—no luck.

You can even change the spark plug and check the gas. Still nothing. It could mean you have a failing ignition coil.

2. Engine misfires

An engine misfire occurs when one of the cylinders fails to fire well. Instead of a smooth, consistent hum, your engine sputters or jerks.

This can happen randomly or become a constant issue, affecting your mower’s performance and efficiency.

A misfire can be due to various factors, but a problematic ignition coil is often to blame. When the coil can’t provide the right voltage to the spark plug installed, the fuel-air mix doesn’t ignite as it should.

Other reasons include a worn-out spark plug or issues with the fuel injectors. But if those are in good shape, your sights should be set on the ignition coil.

Kohler Ignition Coil Problems

3. Engine stalling

Engine stalling occurs when the engine stops running without warning. A faulty ignition coil can often be the cause. The engine can’t maintain its combustion cycle when the coil fails to provide a consistent, strong electrical charge to the spark plugs. The engine then quits on you.

Stalling happens at the worst possible times. Engine stalls are particularly common when you’re:

  • Changing speeds
  • Making sharp turns
  • Navigating tough terrains
  • Starting the mower after it’s been idle

A stall can be hazardous, especially if you mow on an incline or near obstacles.

4. Poor fuel efficiency

If our Kohler engine is guzzling more fuel than usual, the ignition coil might be the culprit.

A faulty coil can disrupt the most fuel-air mix, leading to incomplete combustion, meaning you’re burning through fuel more than you should be and affecting your engine.

Keeping an eye on fuel system efficiency and solving your Kohler engine problems needs routine checks. Here’s a simple tutorial:

  • Record Baseline Data: Note how much fuel you fill up and how long it takes to run out during a standard mowing session.
  • Consistent Conditions: Always aim to mow under similar conditions: same grass height, same speed, etc.
  • Track Changes: Over several mowing sessions, continue to record your fuel usage.
  • Calculate: Divide the total area mowed by the amount of fuel used. If this number declines over many sessions, fuel efficiency will worsen.

5. Engine backfiring

A backfire is a small explosion when unburnt fuel exits through the exhaust system and ignites.

If your Kohler engine is backfiring, a faulty ignition coil may be the reason.

An inefficient coil can disrupt the timing, causing the spark plug lead to fire at the wrong time and leading to incomplete combustion, leaving unburnt fuel that can then backfire.

Also, awareness of the safety risks linked to engine backfires is key.

Backfires can start fires. The small explosion can light up dry grass or leaves near your mower. So, it’s risky if you’re mowing near stuff that can catch fire.

Backfires can also hurt your mower’s engine over time. The extra stress from each backfire can damage other parts of your engine.

Backfires are loud. This noise can harm your hearing if you’re not wearing ear protection. 

6. Check engine light

The check engine light is like a messenger for your Kohler engine. It signals that something’s not right.

While this could be due to various issues, a malfunctioning ignition coil is often a prime suspect.

When the coil can’t convert battery power to the spark plugs, the engine control unit (ECU) triggers this warning light.

Ignoring the check engine light might not cause immediate catastrophe, but it’s a ticking time bomb. You should diagnose and act immediately on these issues.

The light is your first clue to identifying a potential issue before it worsens. Early action can prevent a small problem from escalating into a more expensive repair.

A faulty ignition coil could lead to more severe issues, like engine overheating or stalling, that could put you at risk.

7. Engine overheats

If you notice your Kohler engine running hotter than usual, a faulty ignition coil could be blamed.

When the coil malfunctions, it struggles to provide the spark plug connection with enough power. This inefficiency forces the engine to work harder, leading to an increase in temperature.

Do not underestimate the snowball effect of an overheating engine. Here’s how one issue can lead to another:

  • Reduced Engine Efficiency: An overheated engine performs poorly. It affects your mowing speed and quality.
  • Internal Damage: Extreme temperatures can warp engine parts, making them less effective or causing them to break.
  • Coolant Failure: Overheating often leads to coolant evaporation, reducing its ability to regulate the engine’s temperature. In turn, it exacerbates the overheating issue.
  • Increased Fuel Consumption: Overheating can also cause poor fuel efficiency, costing you more.
  • Safety Risks: Finally, an overheating engine poses a fire risk, especially if flammable materials like oil or dry grass are nearby.

Table Summary: A Quick Reference Guide

ProblemReasonPotential Solution
Poor StartFaulty ignition coil disrupting the voltage to spark plugs.Check and replace the ignition coil. Also, inspect spark plugs and fuel lines.
Engine MisfiresInconsistent voltage from the coil to spark plugs leads to imbalanced combustion.Inspect the ignition coil and replace it if necessary. Also, check spark plugs and fuel injectors.
Engine StallingCoil failure results in an inconsistent electrical charge to spark plugs.Examine and possibly replace the ignition coil. Ensure spark plugs and fuel lines are functioning well.
Poor Fuel EfficiencyDisruption in fuel-air mix due to faulty coil, causing incomplete combustion.Monitor fuel consumption over time; replace coil and regularly check fuel efficiency.
Engine BackfiringIncorrect timing due to inefficient coil, causing unburnt fuel to ignite.Replace the faulty ignition coil and be cautious of surrounding flammable materials. Wear ear protection.
Check Engine LightWarning sign triggered by malfunctioning coil.Do not ignore; conduct immediate diagnostic tests and replace the coil if needed.
Engine OverheatsA malfunctioning coil causes an engine to work harder, increasing the temperature.Replace the ignition coil, regularly inspect coolant, and ensure engine parts are in good shape.

How to Test a Kohler Ignition Coil

1. Spark test

Materials Needed:

  • Spark plug wrench
  • A pair of insulated pliers
  • Safety goggles
  • Insulated gloves

Step-by-step Guidance:

  1. Disconnect the Spark Plug: Use the spark plug wrench to remove the spark plug from the engine.
  2. Inspect the Spark Plug: Look for any signs of wear or damage. Replace it if necessary.
  3. Re-attach the Spark Plug: Securely connect the spark plug to the spark plug wire, but wait to install it back into the engine.
  4. Ground the Spark Plug: Using insulated pliers, hold the spark plug’s metal end against a grounded metal part of the engine.
  5. Safety First: Put on your safety goggles and insulated gloves.
  6. Crank the Engine: Have someone turn the engine over while you look for a visible spark between the spark plug’s electrodes.
  7. Test: A bright blue spark indicates a functional coil. If the spark is weak or nonexistent, the coil may be faulty.
Kohler Ignition Coil Problems

2. How to test Kohler ignition coil with a multimeter

A multimeter measures electrical properties like voltage, current, and resistance, allowing for a more precise diagnosis and can save time and money.

Walkthrough on Proper Usage:

  1. Set the Multimeter: Turn your multimeter to the ohms setting. You’re aiming to measure resistance in this case.
  2. Disconnect the Ignition Coil: Before you start, disconnect the coil from the spark plug and the engine.
  3. Locate Terminals: Identify the primary and secondary terminals on the coil. The primary terminals will be smaller, whereas the secondary will usually be where the spark plug wire connects.
  4. Measure Primary Resistance: Place the multimeter’s probes on the primary terminals and note the reading.
  5. Measure Secondary Resistance: Place one probe on a primary terminal and the other on the secondary terminal. Note the reading again.
  6. Compare: Check these readings against the specified resistance values in your Kohler engine manual. Large discrepancies state a faulty coil.
  7. Make a Decision: If either test shows your coil is faulty, replace it.

Faulty Kohler Ignition Coil Replacement

Replacing a faulty ignition coil is a process that requires attention to detail. 

Tools you’ll need

  • Screwdriver or wrench set
  • Spark plug wrench
  • A new ignition coil compatible with your Kohler engine
  • Safety goggles
  • Insulated gloves

Replacement steps

Step 1: Disconnect the spark plug wire

Start by locating the spark plug wire connected to the spark plug. Gently pull it off to completely disconnect, thus cutting off the electrical circuit and eliminating the chance of the engine starting up accidentally.

Wear insulated gloves for extra protection against electrical discharge while handling the wire.

Step 2: Removing the blower housing

The blower housing usually has many screws or fasteners holding it in place. Use a suitable screwdriver or wrench to loosen and remove these. Keep them safe because you’ll need them for the reinstallation process.

Consider using a small container or magnetic tray to hold the screws so they don’t get lost.

Step 3: Removing the ignition coil

Once the blower housing is removed, you’ll have clear access to the ignition coil. It’s generally secured with screws or bolts.

Unscrew these and remove the coil, taking note of its orientation and the position of spacers or washers.

Taking a quick photo before removing it can serve as a helpful reference for installing the new coil.

Step 4: Installing a new one

Place the new ignition coil in the same position as the old one, aligning it with the screw holes. Start inserting and tightening the screws or bolts but don’t fully tighten them yet.

Use a feeler gauge to check the gap between the coil and the flywheel. This gap is critical for proper functioning. Check for specifications in your Kohler engine manual.

Step 5: Installing the blower housing

Align the blower housing with its respective mounting points on the engine. Reinsert and tighten the screws or fasteners you removed earlier.

Ensure that all fasteners are well-tightened. Loose parts can vibrate during operation, leading to potential damage or malfunction.

Step 6: Connect the spark plug wire

Finally, find the end of the spark plug wire and push it onto it until it clicks firmly in place, ensuring a solid electrical connection, which is crucial for ignition.

A loose connection can lead to arcing, which affects engine performance and could be a fire hazard.

How to replace flywheel magnets

The flywheel is more than just a heavy, spinning disk. It contains magnets crucial for generating the electrical energy your engine needs.

When these magnets fail, your ignition system and, by extension, your engine can suffer from poor performance or even fail to start.

The flywheel magnets help create the electrical pulse to fire the spark plug and ignite the fuel-air mixture. 

Kohler Ignition Coil Problems

Signs of a Failing Flywheel Magnet

  • Engine Misfires: If your engine starts but runs unevenly, the flywheel magnet could be to blame.
  • Poor Starting: Difficulty in starting your engine, even after many attempts.
  • Inconsistent Engine Idle: An engine that revs up and down while idling could be experiencing flywheel magnet issues.
  • Weak Spark: If you test the spark and it appears weak, this could also point to a failing flywheel magnet.

Tools You’ll Need:

  • Screwdriver or Wrench set
  • Feeler Gauge
  • Hammer and Punch (optional)
  • New Flywheel Magnets
  • Insulated Gloves
  • Permanent Marker

Steps to replace flywheel magnets

  1. Disconnect the Spark Plug Wire: Start by disconnecting the spark plug wire to drop the risk of accidental ignition.
  2. Remove the Flywheel Cover: Locate the cover, usually held by a series of screws or bolts. Remove these and lift off the cover, storing it and the screws safely for reassembly later.
  3. Mark the Flywheel Position: Use a permanent marker to mark the current position of the flywheel relative to the engine, making it easier to align when reinstalling.
  4. Loosen the Flywheel Nut: Use an appropriate wrench to loosen the flywheel nut that secures the flywheel to the crankshaft. You may need a hammer and punch to tap it loose.
  5. Remove the Damaged Magnet: Once the flywheel is loose, rotate it to locate the damaged magnet. Pry it off using a flat-head screwdriver.
  6. Install the New Magnet: Place the new magnet in the same position as the old one, ensuring it aligns with the marked areas for polarity.
  7. Tighten the Flywheel Nut: Align the flywheel according to the mark you made earlier and tighten the flywheel nut.
  8. Reassemble and Test: Reattach the flywheel cover, secure it with its screws, and reconnect the spark plug wire. Test the engine to ensure it’s functioning well.


How much does replacing an ignition coil in a Kohler mower engine cost?

The cost of replacing an ignition coil in a Kohler mower engine varies based on labour rates and the specific model of your mower. But you can generally expect to pay between $50 to $100 for the ignition coil part alone. With labour included, the total cost may range from $100 to $200. Always consult a professional for an accurate estimate.

Can a faulty spark plug cause Kohler Ignition Coil problems?

A faulty spark plug itself won’t cause Kohler Ignition Coil problems.  But it can contribute to engine performance issues.  If your engine gets too much air and fuel, the spark plug can develop problems. These spark plug issues may lead to its failure over time. So, a bad spark plug can impact the longevity and performance of your ignition coil.

What is the difference between an OEM Kohler Ignition Coil and an aftermarket one?

Kohler itself makes an OEM (Original Equipment Manufacturer) Kohler Ignition Coil. It’s designed to fit and work perfectly with your Kohler engine. Another company makes an aftermarket coil, which might be less expensive. But, it may have a different quality or fit and an OEM part. Both can work, but OEM is often safer for long-term reliability.

What is the warranty on a Kohler Ignition Coil?

The warranty on a Kohler Ignition Coil can vary depending on the specific product and where you buy it. Kohler offers a limited warranty ranging from one to three years for most parts, including ignition coils. It’s crucial to check the warranty details for your specific model and ensure you keep your proof of buying. 

Why is my Kohler engine not firing?

If your Kohler engine isn’t firing, there could be various reasons, but a common culprit is often the spark plug. Check the spark plug for any wear, cracks in the porcelain insulator, or signs of carbon buildup at the electrode. The spark plug likely needs replacing if you find any of these issues. To confirm, you can use a spark plug tester. If the tester shows the spark plug is defective, replace it to get your engine firing again.

Next, read on The Problems of Kohler Fuel Pump.


Keeping an eye on your Kohler ignition coil maintains a smooth engine performance. From poor starts and engine misfires to issues like stalling and backfiring, a faulty coil can lead to many problems that disrupt your mowing experience.

Testing the coil, being aware of warning signs, and knowing how to replace it ensure your engine’s longevity and safety.

Ignoring these signs could turn a small issue into a costly problem. So, proactive maintenance is key.