Why My Lawn Mower Stopped While Running? Causes and Fixes

It is really frustrating when you are working with your lawn mower and suddenly it stops while running. There can be a lot of reasons why you are facing this problem. 

Usually, clogged fuel lines, dirty air filters, and engine problems are the main reasons why your lawn mower stopped while running. 

In this article, I will try to explain all the reasons and their fixes that you can do by yourself. 

Why My Lawn Mower Stopped While Running

Reasons for Lawn Mower Stopped while Running (Fixes Added)

There can be several reasons why your lawn mower has stopped working while running. Here are the reasons and the fixes that you can do all by yourself:

1. Old Fuel:  

The main reason for a lawn mower stopping is an old fuel tank. The fuel in the mower’s tank could become contaminated if it hasn’t been used for a while. And this can make your mower suddenly stop while running.


Drain old fuel from the tank and replace it with fresh, clean fuel. If this doesn’t fix the issue, you might also need to look into, the fuel filter.

To prevent fuel-related issues in the future, consider using a fuel stabilizer. Fuel stabilizers help prevent the breakdown of gasoline and keep it fresh for a longer period. 

Simply add the recommended amount of stabilizer to your fuel tank before filling it with gasoline. This will help ensure that your fuel remains in optimal condition, reducing the risk of clogs and engine stalls.

2. Dirty Air Filter: 

A dirty or clogged air filter can restrict airflow to the engine, causing it to stop. Remove the air filter and inspect it for dirt, debris, or damage. 

If it is dirty, clean it with a blow dryer or replace it with a new one. Regularly cleaning or replacing the air filter is important for maintaining proper engine performance.

3. Bad Carburetor: 

The carburetor is a vital component of the lawn mower’s fuel system. Over time, it can become clogged with debris and varnish buildup, leading to engine performance issues. 


To fix this you just have to clean the carburetor. To clean the carburetor, start by removing the air filter and spraying the carburetor cleaner into the carburetor throat and all accessible openings. 

Allow the cleaner to sit for a few minutes, and then use a brush to scrub away any residue. Reassemble the carburetor and try starting the mower again.

4. Worn-out Spark Plug:  

A faulty spark plug can cause the lawn mower to stop running. Remove the spark plug and check it for signs of damage. If the spark plug is dirty or covered in deposits, clean it using a wire brush. 

Fix: If the spark plug is damaged or worn out, replace it with a new one that matches the manufacturer’s specifications.

5. Overheating Engine: 

Overheating can make the mower stop while running. A mower gets overheated when there is debris building up in the cooling fins. This makes the ignition coil fail. The environment temperature is another factor but that is negligible. 

To fix this make sure you have a clean fin and the air filter is clean. Sometimes low engine oil can make the engine overheat so ensure the mower has enough engine oil to function.

6. Safety Feature: 

Some mowers have safety switches that prevent the engine from running if the operator is not sitting in the seat or if the PTO switch is not properly engaged. A faulty safety switch can also cause the lawn mower stopped while running.

This is not a bad thing for a lawn mower. Featurewise it is a good thing but faulty safety switch sometimes get triggered on their own and stops the engine. 

To fix this issue you should call the customer care center of the mower. And if the warranty is expired, you should call a professional.

7. Bad Ignition system: 

The ignition system is responsible for creating the spark that ignites the fuel-air mixture in the engine. A malfunctioning ignition system can cause the lawn mower stopped while running. 


Check the ignition coil, spark plug wire, and other ignition system components for any signs of damage. If any components are faulty, replace them to restore proper ignition. 

To do this you might need professional help as it is a bit tricky to fix the ignition system on your own.

8. Faulty Blades and Cutting Deck: 

A dull or damaged blade can put excessive strain on the engine, causing it to stall. Check the blade for wear or damage. If the blade is dull, sharpen it using a file or replace it with a new one. 

Additionally, make sure the blade is screwed to the mower deck to prevent any vibrations.

A buildup of grass clippings, dirt, and debris can hinder a mower’s performance and lead to an engine stop. 


Regularly clean the cutting deck to remove any accumulated debris. Use a brush or scraper to scoop the stubborn clippings and clean the deck with water. It will improve airflow and prevent clogs, allowing the engine to run smoothly.

How to Solve Lawn Mower Stopped While Running

These are the steps how you can troubleshoot a lawn mower stop issue while running:

Check the fuel tank: Make sure that the fuel tank is not empty. 

Check the fuel lines: If the fuel lines are clogged, clean them out. Check the carburetor if the fuel line is well connected.

Check the fuel filter: If the fuel filter is dirty, replace it. If you use your lawn mower on a regular basis, the fuel filter should be in good condition. Idle machines make debris in the fuel filter.

Check the air filter: If the air filter is clogged, clean or replace it. Every time you are done with mowing clean the air filter. That’s why you can keep the filter easily.

Check the spark plug: If the spark plug is dirty or worn out, clean it and fix it. If it is damaged, replace it. You always should be aware of the condition of the spark plug as it gets dirty so easily.

Check the engine oil level: Make sure that the engine oil level is not low. Excessive oil makes the lawn mower stopped while running too. So you have to fill the engine oil at the right amount.

Check the engine temperature: If the engine is overheating, wait for some minutes to cool down before trying to start it again. If it is really hot outside, then try avoiding mowing if that is not necessary.

Check the safety switches: Make sure that all of the safety switches are working properly.

Check the blades: you have to ensure the blades are sharp and in good condition as dull blades give the mower engine excessive pressure that sometimes lead your lawn mower stopped while running.

Frequently Asked Questions (FAQs):

Why is my lawn mower dying while running?

If your lawn mower keeps dying while running that means the mower has a bad spark plug in it. You have to check the spark plug and replace it.

How do I know if my lawn mower carburetor is clogged?

Some obvious symptoms can tell your carburetor is clogged. 

These are: the engine has trouble starting, the engine stalls when starting, the engine runs rough, and excessive fuel consumption.

How do you clean a carburetor on a lawn mower without removing it?

Use a Carburetor Cleaner. It allows you to clean the carburetor without removing it.

What kind of oil do you put in a lawn mower?

SAE 30.

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