Kohler Engine Runs Then Dies: Causes and Fixes

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Is your Kohler engine stalling? Does it run for some time but then dies before you can get a reasonable amount of work done? This can happen for several reasons.

In this article, I share some of the common reasons your Kohler engine might run then suddenly die, troubleshooting tips to diagnose and fix the problem, plus helpful routine checks to keep your Kohler lawn mower engine performing optimally.

Reasons Why Your Kohler Engine Runs Then Dies

Some of the reasons your Kohler engine runs for some time and then dies include:

  • Clogged carburetor
  • Clogged fuel cap vent 
  • Insufficient or stale oil
  • Faulty spark plug
  • Ignition coil malfunctions

Kohler Engine Runs Then Dies: Causes And Fixes

1.  Clogged Carburetor


Leaving fuel in your Kohler engine for more than a year can result in a clogged carburetor. Some of the components in the fuel may evaporate over time, leaving a thicker, stickier substance behind. 

Also, grass, twigs, debris, and grime can find their way to the carburetor passages over time, and clog the engine.

These deposits clog up the carburetor and fuel passages, reducing overall engine performance. The engine may die after running for some time because of this.


  • Use a carburetor cleaner to clean and unclog the carburetor if it’s clogged. 
  • Replace the entire carburetor if cleaning it doesn’t work.

2. Clogged Fuel Cap Vent – Vapor Lock

The fuel level in the tank decreases as fuel is used by the engine. The fuel tank of most lawn mowers utilizes a tiny air vent cap that lets air into the tank to prevent a vacuum from forming. 

When this fuel cap vent is blocked, air cannot enter the tank, which leads to a vapor lock. The engine stalls as a result of this, stopping the fuel delivery to the carburetor. The engine, therefore, dies after a few minutes because fuel is not able to get into the carburetor.


  • Try slightly loosening the fuel cap before starting the engine to see whether the vent is clogged. 
  • If the engine runs effectively after making the fuel cap loose, the fuel cap vent is blocked and has to be replaced with a new one.

3. Insufficient or Stale Engine Oil

The function of the engine oil of a vehicle is to lubricate the moving parts. When the oil available in your lawn mower’s engine is small or insufficient, the moving parts lack lubrication and will shut down after some time.

Stale engine oil can also be the culprit. The color of fresh engine oil is a golden/amber color. With frequent use, heat generated by the engine, engine dirt, tension, and friction cause the oil to darken and become stale.

Dark and stale engine oil has lost its ability to coat and properly lubricate the moving engine parts, leading to excessive friction and overheating.

This friction and overheating can cause your Kohler engine to shut down after running for a short time.


  • Check the oil level and quality using a dipstick. Top up the oil tank with new oil if it is small or insufficient. 
  • Change/replace the oil completely if it is dark and stale.

How To Check Lawn Mower Oil Level:

  • Power off the engine and allow it to cool for some minutes 
  • Open the oil tube and clean the dipstick with a neat cloth. The dipstick is attached to a bright yellow ring
  • Take note of the oil marks on the dipstick ‘F’ and ‘L’ indicating ‘Full’ and ‘Low’
  • Enter the dipstick back into the tube and pull it out to check where the oil falls
  • Do this about 2-3 times to ensure an accurate reading. The oil level should be between the ‘Full’ and ‘Add’ marks.

NB: Always check the oil level after refilling the oil. Make sure it is never above the Full mark or below the Add mark.

How To Change Kohler Engine Oil:

  • Turn off the engine and disconnect the spark plug lead, keeping it away from the spark plug
  • Locate the oil fill cap and drain out the old oil
  • Refill the oil tank with new oil

Be careful not to overfill the tank as too much oil can also cause damage to your Kohler engine.

4. Faulty Spark Plug


If your Kohler engine dies after running for a few minutes, it may be because the spark plug isn’t providing a strong enough spark. 

In this instance, heat is the real culprit for the failure of the spark plug. Spark plugs experience wear and tear over time as a result of frequent heating, cooling, and reheating of the engine. 

A faulty spark plug will fail to properly ignite the fuel-air mixture and the lawn mower will die after some time because of this.


  • Carry out a spark plug test to determine if the plug is producing a spark. 
  • Replace the spark plug with a new one if it fails to produce a spark.

5. Ignition Coil Malfunctions

If the problem persists after changing the spark plug, the ignition coil also known as the starter coil might be the cause of the problem.

A lawn mower’s ignition coil is an essential part of the engine. It is in charge of transferring power from the battery to the spark plug, which creates the spark that ignites the mower. 

There is a strong likelihood that the ignition coil is malfunctioning if your mower dies after some time because it is not generating sufficient power needed to support the spark plug.


You will need to replace the ignition coil if your new spark plug doesn’t spark after you’re certain that you’ve tested it properly. 

Unless you have some experience and are quite confident in your technical skills, I would advise consulting a small engine technician for this job.

How To Perform Routine Check On Kohler Engine

Performing a routine check on your Kohler engine helps to prevent future reoccurrences of engine problems and keeps your engine in good working condition. This can be done annually or before the start of a new mowing season.

1.  Change your lawn mower oil

Your lawn mower oil should be changed at least after every 50 hours of use, usually once every spring or summer. 

Changing your engine oil when due will keep your lawn mower running well for years to come. You should also check the oil level before every use to know if it needs to be increased or topped up with more oil.

2. Change the spark plug

The spark plug of a Kohler engine has a standard lifespan of about 25 hours. Your lawn mower’s spark plug will wear out after a complete season’s use. Ensure to replace it when needed.

3. Drain the fuel and check the fuel filter for impurities

Usually, after storage seasons, the fuel tank will be filled with impurities that are harmful to your engine. Drain out the old fuel and check the filter for impurities before adding new fuel to the tank.

4. Clean or replace the air filter


A blocked or dirty air filter will reduce engine performance and significantly increase your lawnmower’s fuel consumption. A clogged air filter might also make the engine stall or stop running after some time.

It is best to replace a dirty or clogged air filter to ensure optimum performance of your Kohler engine.


The reason why your Kohler engine runs and dies after a few minutes might be due to: a clogged carburetor, clogged fuel cap vent, faulty spark plug, or stale oil.

Take some time to inspect the various parts and apply the recommended fixes stated in this article to stop your engine from shutting down after running for some time.