Why Is My Kohler Engine Runs Then Dies? [Easiest Fix Ever!]

Kohler engines, used in lawnmowers, can run and die for many reasons. However, the common cases are clogged fuel cap vents, damaged piston rings, jammed carburetors, stale oil, overheating, and faulty ignition coils. 

The recommended steps to fix the “run then die” problem are unclogging the fuel cap vent, installing new rings on the piston, cleaning the carburetor, and replacing the malfunctioning ignition coil. Moreover, avoiding overheating and adding more oil to the engine can fix the problem.

In this article, we will discover the points causing the Kohler Engine Runs Then Dies and learn their easy fixes.

Go through the below sections to learn about each reason in depth and their general fixing procedure to try.

1. Clogged fuel cap vent

fuel cap vent
fuel cap vent

Fuel cap vent clogging is the most common reason the engine runs and dies after some time. The cap has a small hole so air can enter the fuel tank. The hole is crucial to avoid air pressure build-up or vacuum and prevent explosion. If it becomes clogged, it creates a vacuum and stops the Kohler engine.

How to fix:

  • Open the cap and check the vent. Clean the hole with dry and spiky objects, like a small wire or paper clip, if the hole is clogged with dirt.
  • Poke through the vent to remove dirt. You can also use compressed air for good cleaning results.
  • After cleaning the vent, close the fuel tank with the cap and restart the engine. If the cap is damaged or badly clogged, replace it.


Do not smoke while opening the fuel cap. Work in an open place to avoid inhaling fuel fumes. 

2. Damaged piston rings

piston ring

These rings work as a seal between the piston and the cylinder wall. Due to consistent usage, particles, and improper installation, they can be damaged. As a result, the piston rings cannot create the seal and cause oil leakage in the combustion chamber. Finally, the engine stops without any warning.

How to fix:

  1. Replacement is the only option for damaged piston rings. First, remove the piston from the engine’s block and detach those rings from the piston.
  1. Install new rings on the piston and reassemble it in the engine block. Restart the engine and see if it works.


Wear safety gloves to avoid cuts from the piston rings.

3. Clogged carburetor


It is a big reason that a Kohler engine runs and then dies. Dust, oil waste, and malfunctioning internal components can jam the carburetor. Once it is clogged, the carburetor fails to mix the air and fuel properly and shuts down the engine suddenly.

How to fix:

  1. Remove the carburetor from the engine and disassemble it. Clean all its parts carefully. You should use a carburetor cleaner for the best cleaning result.
  1. Use compressed air to clean the carburetor’s throat, bore, and barrel. After cleaning, reassemble and reinstall the carburetor. Start the engine after the installation. 
  1. If the carburetor seems permanently damaged, replace it with a new one.


Use the right tools to disassemble the carburetor. Also, do not rush while removing it from the engine.

4. Insufficient or stale oil

stale oil

Oil is crucial for lubricating the engine’s moving parts. It is also essential to prevent wearing out the internal components. If the engine lacks sufficient oil, excessive friction can happen, which restricts the engine’s movement.

Inadequate oil is also the reason for the engine’s overheating and sudden inactivity. Moreover, stale oil often makes the engine difficult to start.

How to fix:

  1. If the engine dies for these reasons, adding new oil is the solution. Choose a compatible oil for the Kohler engine first.
  1. Drain old oil and add sufficient and fresh oil to well-lubricate the engine. After that, restart the engine and notice it the problem is solved. 


Do not smoke while changing the oil. Also, keep all types of flame away. Choose a well-compatible and high-quality oil to maximize the engine’s performance.

5. Overheating

Due to overheating, Kohler engines can suddenly die. Excessive heat sometimes vapor locks the carburetor and stalls the engine. When the engine is overheated, its metal parts expand and cause friction, which results in an engine failure.

How to fix:

  1. First, address the reason for overheating. For example, if the engine becomes too hot after a specific time, pause mowing before reaching that time. There are many other reasons for overheating, which you must find out and fix accordingly.
  1. Check the engine’s coolant level. Add more coolant with an accurate mix ratio if the level seems low.
  1. A defective thermostat may not distribute coolant through the engine. In such a case, replace the faulty one to protect the engine.


Before working on the engine, wait until it becomes cool. Avoid the coolant from skin contact at any cost, as it is highly toxic.

6. Ignition coil malfunctions

Ignition coil malfunctions

The ignition coil’s key function is to create a high-voltage spark needed to operate the spark plug. If it does not work correctly, the generated spark can be weak and result in the engine shutting down during operation.

How to fix:

  1. Overheating is often responsible for the ignition coil failure. Check the engine’s cooling system and fix it if you have found any issues.
  1. Corrosion can also cause an ignition coil to malfunction. In that case, clean the coil with an electric contact cleaner.
  1. Excessive engine vibration hampers the connection between the ignition coil and spark plug. Ensure that the coil is mounted correctly and tightened.
  1. If the ignition coil looks too old and worn out, replace it with a new one.


Use the right tools to detach the ignition coil to avoid physical damage.

Accidental Shut Off or Stalling: Signs You Must Notice

A Kohler engine can run and then die for several reasons. However, you need to confirm if it is occurring repeatedly. 

Here are the scenarios indicating the engine has stalling issues.

Frequent shutdown:

If the engine has a staling problem, you may notice frequent engine shut-offs during mowing. It can happen in both idle or active mode of the engine. Also, the crash maintains a certain amount of time. For example, the engine stops every 15 minutes. 

Low power performance:

It is normal that sometimes the engine shuts off during operation unintentionally. But it should not impact the engine’s power. In the case of stalling, the engine’s performance seems weaker. You can experience low power from the engine, even with the high RPM. 

Difficult starting:

Once the engine shuts down, it is difficult to start. You may even fail to start it with multiple attempts. This is a common sign of the engine’s malfunction, not the typical shutdown. Also, you may notice rough idling and weird noises from the engine.  


In the case of an accidental shut-off, the engine can die after running without overheating. But, the engine will be excessively hot when it has a stalling problem. It indicates whether it is a normal shutdown or a prior sign of malfunction.

in verdict – Preventive Tips for Kohler Engines Runs and Dies Problem

Engine stalling is not always bad. The safety features sometimes can switch off the engine as a protection. However, repeated stalling is harmful to the engine as it enhances the risk of wear and tear. Besides, the repetition can reduce the engine’s lifespan.

Here are some tips to prevent the repeated “run and die” problem for Kohler engines:

  • Ensure the engine’s cooling system works appropriately, like the cooling fan.
  • Check the coolant level routinely. Add more coolant if needed.
  • Change the engine oil following the manufacturer’s guidelines.
  • If not necessary, avoid mowing in excessively hot weather. 
  • Keep all types of filters clean, including the air and fuel filter and the engine’s cooling fins.
  • Unclog components whenever you notice them jammed.
  • Understand the capability of the engine and avoid overusing or overloading.
  • Based on the usage, bring the lawn mower to a technician every six months to one year for professional servicing.

Kohler Engine Runs Then Dies related [FAQs]

Q. Why does my Kohler engine not start at all?

The problem is relevant to insufficient fuel, ignition system malfunction, and compression issues. It is a different issue from the engine stalling and has specific fixing. 

Q. Why does the engine not shut down after starting?

It can happen if the engine has a problem with the ignition switch, vacuum leakage, and faulty fuel solenoid.

Q. What to do if the engine still runs and dies after fixing those problems?

If your lawn mower has a warranty, contact the manufacturer first. They will provide you with a precise guide. If the warranty is expired, bring it to a technician to address and fix the issue.

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