Lawn Mower Won’t Stay Running?

Lawn Mower Won't Stay Running

I was mowing the lawn and suddenly my lawn mower wouldn’t stay running. I tried starting it again but nothing happened. The engine just kept turning over without firing up and my Lawn Mower Won’t Stay Running?

What could be wrong? How to do troubleshooting of my lawn mower? Could it be clogged carburetor?

I checked all of the usual things like gas, oil, spark plugs, fuel filter etc., but everything looked okay so I took it in to a local repair shop for an estimate. They told me that they would have to order some parts before they could tell me what was wrong with it or how much it would cost to fix.

Lawn mowers are apparently simple machines but operating them smoothly requires some work. A lawn mower engine is essentially a simple air pump. Like any pump, its job is to push gas and air mixture into the combustion chamber where it will ignite.

To do this, the air-and-gas mixture passes through a carburetor , which mixes gasoline with air in just the right proportions. The caraburetor then routes the mixture into the engine’s combustion chamber through a series of tubes called intake and exhaust ports. The porting system makes it possible to get an even flow of fuel-air mixture to all areas of the engine.

The lawn mower’s camshaft has lobes that cause valves to open at just the right time in order for this fuel-air mixture to enter the combustion chamber, which is where the magic happens.

The spark plug fires up when it receives and electrical charge that ignites the fuel-air mixture. A precise amount of time before this happens, the valves have already opened and sucked air into the combustion chamber while simultaneously routing the fresh mixture in through another set of valves.

However, if any of these systems stops functioning correctly, the engine will sputter and eventually fail to start up.

In my case, I somehow managed to get a little piece of grass caught in a channel between the intake and exhaust valves that was blocking the gas flow into the carburetor. My lawn mower needed some minor surgery to remove the grassy obstruction.

I checked my lawn mower out after paying a small fortune for it and I got ready to start her up again, but this time instead of just turning over without firing, she fired right up and was running smooth as silk again! Now that’s what I call great service!

Lawn Mower Won't Stay Running

Now that’s what I call great service!

It was a simple fix but the question is, how many people would have been willing to pay a small fortune for this seemingly simple repair? The majority of people would have thrown their lawn mower away and bought a new one, never knowing that it could be repaired. That’s why today we’re going to learn how to fix our own lawn mowers and save ourselves some money in the process!

What’s good is that if you take just a few minutes to find out what’s wrong with your machine, it won’t cost you an arm and a leg to get it repaired. The majority of lawn mower repairs are fairly simple fixes! Most of them just require a little bit of time and the right parts.

In this article I am going to show you how to fix your own lawn mowers in 6 easy steps so that you can save big dollars over having them repaired at your local repair shop!

Lawn Mower Won’t Stay Running?

Here are 6 simple do-it-yourself lawn mower repairs that you can do in your own garage:

1. Replacing Spark Plug

The spark plug lies close to the engine’s combustion chamber and is one of the first components that wears out. It gets extremely hot during operation which causes it to wear down faster than other parts of the mower . When this happens, you’ll have problems starting up your mower because the spark will be weak and you’ll have to use more effort than usual.

Getting a new spark plug is relatively cheap (about $2-3) and shouldn’t take longer than 5 minutes to install.


You need to remove the old spark plug first before installing the new one. This can be done with a simple wrench. Make sure you wear gloves as the spark plug can be very hot sometimes! Make sure to thoroughly clean off any dirt that is stuck on the electrical connectors before installing your new sparkplug . This will ensure a good connection between the sparkplug and the engine’s wiring system.

Then, using your socket wrench again, install a new sparkplug into the engine. Make sure you screw it in with a light force so that you don’t strip the head of the spark plug and cause permanent damage to the machine. After that, simply start up your mower again and see if it starts from just one pull of the starter cord. If it doesn’t, then do the same thing again.

2. Cleaning the Air Filter 

Next to the spark plug, the air filter is one of the components that gets damaged first because it’s right in front of the engine. It filters any dust or foreign particles from entering into your mower and causing damage to other important mechanical systems inside. When your air filter gets clogged with dust and dirt, it will also reduce the amount of air that is able to get into the engine. This causes a lack of combustion and leads to weak starting problems as well as poor performance during operation.


Most lawn mower models have a removable air filter which can be cleaned . To find out if your model has this feature, simply check your user manual. The air filter is usually placed on the upper part of your mower and is very easy to remove. Simply unscrew the screws that are holding it in place, make sure you have a new one (these cost about $5) and install it over the engine’s air ventilation vents .

3. Replace Your Lawn Mower’s Spark Plug Wires

Spark plug wires provide a good and strong connection between the spark plug and the mower’s ignition system. However, over time they wear out causing your lawnmower to misfire and not start up correctly. When this happens, your engine may stall at random times or perform poorly during operation. This can also be a sign that your actual spark plug is already damaged.


In order to fix the spark plug wires, you must first disconnect them from the ignition system of your mower . Use an adjustable wrench and loosen up the wire connector. Next, you can simply replace it by attaching a new wire in its place. However, be careful in choosing the correct length so that you don’t cause any electrical damage to your mower.

4. Replacing the Starter Cord/Cables 

The starter cord is what makes it possible for you to start your lawn mower by simply pulling a lever. It’s made up of a cable coiled around a spring and is placed inside a cylindrical housing. The starter cord is just like your car’s ignition system except that it is usually much smaller and lighter .


Replacing the starter cord of you lawn mower is an easy job. In order to do this, simply disconnect the old starter cord by loosening up its clamp with an adjustable wrench. Then, follow the existing starter cord until you see where it connects to the engine’s flywheel. From here, you can simply attach a new one by looping it around and clamping it in place. Make sure you use only high quality cables that are designed specifically for lawn mower starters .

5. Replacing Engine Brushes 

Engine brushes are used to conduct electricity from the ignition coil to the spark plug. They come in different shapes and sizes depending on your lawn mower’s model but usually have a silver or gold color .


If your engine has worn out brushes, it will cause weak starting problems as well as poor performance during operation. Usually, these problems begin to occur after a year or two of regular use. To fix this, you must first disconnect the spark plug from the cylinder head and remove the air filter cover so that you can access the engine housing. Now check the brushes by removing their pivot pin and using an ohmmeter to measure if it’s still good . If not, then you must replace it with a new one.

6. Replacing the Ignition Coil 

The ignition coil is a device that makes use of an electrical current to create the spark needed for ignition. It is usually placed underneath your mower’s engine in either plastic or metal casing and has several terminals attached to its body .


One of the problems that can cause poor performance and inefficient fuel consumption is when the ignition coil has become damaged or worn out. Such problem can usually be detected during cold weather because your mower will have a hard time starting up . Therefore if you experience such symptom, it’s best to replace the ignition coil with a new one in order to restore proper starting and engine performance.

Most of these parts can be purchased at your local hardware store. You may have to spend a little more on these than you would with a generic part, but the cost is worth the peace of mind knowing the job was done right . Also, having original manufacturer replacement parts will also help extend the life of your lawn mower.

In general, you may have to consider replacing your lawn mower’s parts at least once a year or every time it reaches 500 hours of use . This is because wear and tear due to various elements are inevitable and will be more pronounced in older equipment . By taking some preventive measures when using your lawn mower such as properly maintaining the engine and fuel quality , you can extend its life by several years.

If you follow the steps here, I’m sure you’ll have no problems doing basic lawn mower repairs and maintenance work. And remember to get a manual for your model just in case you come across some specific issues that are not covered in this article.

Happy mowing!

References: What Is Wrong If My Push Mower Won’t Continue to Run After I’ve Started it?

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