Why My Lawn Mower Stops Running After A While? Expert’s Interview


The lawn mower market is huge, and it is expected to exceed 23 billion dollars by 2021 globally. The maintenance of lawn mowers is an important task for gardeners. Unfortunately, gardeners often experience several problems while using this cutting tool. Have you ever wondered about this question: why does my mower keep dying?

Why my lawn mower stops running after a while?

Three things are necessary to run a lawn mower smoothly: fuel, air, and a spark. If your lawn mower lacks any of these three things or you failed to mixed them appropriately (not too much nor too little), your lawn mower may stop running after a while.

Why My Lawn Mower Stops Running After A While?

Why My Lawn Mower Stops Running After A While

Why does my lawn mower shut off while mowing? It depends on various reasons as per your lawn mower. Here are them:

Grimy Or Damaged Spark Plugs

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A spark plug does the job of igniting the air/fuel mixture in your engine by producing a “spark.” When spark plugs become grimy or damaged, it fails to do this function properly.

A dirty or damaged spark plug may prevent your lawn mower from starting or die after running for a while.

To know more read the following article – What Causes A Lawn mower Spark Plug To Turn Black? How to Clean?

Mower Running On Old Gasoline

Why My Lawn Mower Stops Running After A While - Mower Running On Old Gasoline

You can operate your lawn mower without gasoline. However, you can’t overlook the quality of the gasoline too.

When the gasoline has not changed for a long time, or the machine sits idle for several months, a damaging residue has probably been created due to evaporation.

Your mower becomes clogged by the residue left by this process. As a result, the gas can’t flow smoothly and freely.

It makes the machine die after running a short period every time you start it. Sometimes, you may even fail to run it even after trying to switching on it.

Choking Issue

Why My Lawn Mower Stops Running After A While - Lawn Mower Choking Issue

Almost every lawn mower comes with a choke to alter fuel-to-air combination. As the mixture warms up, the engine runs continuously.

As long as there is no cooler temperature for some time, it is better to turn off the choke to stop the engine from being overfilled with the incorrect combination of fuel.

However, if you keep the choke idle for a long time, the combustion chamber might be overflowed with fuel. It will ultimately make it frozen and stalls.

Under this situation, you want to leave the lawn mower idea for a few hours. Fuel drains from the combustion chamber when it sits idle.

Turn off the choke and restart it, and check out whether you can run the mower smoothly.

Faulty Gas Cap

Why My Lawn Mower Stops Running After A While - Lawn Mower Faulty Gas Cap

Another possible reason could be a faulty gas cap. Though several types of gas caps are available, vented gas caps are most common for lawn mowers.

Using a vent, the gas fumes in the tank can escape while air is allowed to enter. Occasionally, you may see the check valve is not working properly, and it doesn’t support the air to go through the tank. But you will not face any issue running the lawn mower normally.

Better buy a new one.

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As you know, mowers run through fuel. Without sufficient fuel, it can’t run for long. So a vacuum slowly forms in the fuel tank as the level of fuel falls. When the fuel is consumed, space is filled with air.

With 15-20 minutes, the vacuum becomes pretty hard. No fuel flow will occur to the carburetor, which will ultimately cause the lawn mower to stop after running a while.

Clogged Or Dirty Carburetor

Why My Lawn Mower Stops Running After A While - Clogged Or Dirty Carburetor

Sometimes, the carburetor of your lawn mower can be the reason for this question: why my lawn mower stops running after a while?

It is a common scenario in colder areas, where your machine sits idle for several months. As a result, during the warmer months of the year, your mower will work harder.

Whatever the reason, you want to take care of the carburetor properly.

Without the right amount of air and fuel, you can’t run your mower smoothly, and a carburetor ensures this accurate mixture.

If the carburetor becomes dirty or has some clog-up issues, it fails to do its function. Therefore, your lawn mower may stop running after a while.

Excessive Amount Of Oil

Why My Lawn Mower Stops Running After A While - Lawn Mower overflowing oil tank Oil

Oil is necessary to run a lawn mower smoothly. But that doesn’t mean you will keep more than needed oil in the tank.

So, what is the possibility to determine you have kept too much oil or not? When you do not see any of the reasons mentioned above, it can be associated with this problem.

The engine will emit white smoke when it is overheating due to excessive oil. It’s possible that the mower maybe works if smoke is evaporating in significant quantities.

However, you can only run the machine for a few minutes, and it will stop after a while. Excessive oil breaks down the function of the machine and stops it from working smoothly.

Dirty Air Filter

Why My Lawn Mower Stops Running After A While - Lawn Mower Dirty Air Filter

When you want to know why my lawn mower stops running after a while, the dirty air filter can be one of the reasons too.

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You want to make sure the right level of air enters inside the gasoline for the ignition process. Unfortunately, when the air filter becomes excessively dirty, you can’t expect unrestricted airflow.

Power Supply Issue

Why My Lawn Mower Stops Running After A While - Lawn Mower Power Supply Issue

Sometimes, the question of why does my lawn mower shut off while mowing may be related to a battery-powered lawn mower.

Do you always keep the mower plugged in a while using it or only use it after giving it full charge? Whatever the reason, you want to ensure there is no power as you are not using fuel to operate it.

Mower Blockage Issue

Why My Lawn Mower Stops Running After A While - Mower Blockage Issue

A lawn mower may stop after a while if there is any blockage issue by long grass or grass clippings.

Sometimes, the blades of the lawn mower can be clogged up by grass clipping. When you run the machine for several minutes, grass clippings prevent the blade from cutting grass. It ultimately stops the machine from working.

Similarly, excessive long grasses can also block the mower from running and even break it down.

Defective Or Lack Of Sharpness Blades

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Cutting thicker grass requires sharp blades for mowers. If there is no sharpness on blades or they have become defective, you can’t cut the grass properly. As a result, the machine will stop after cutting for a while.

This could also happen if blades are loose. So make sure you attach the blades before cutting the grass.

Compression Issue

Why My Lawn Mower Stops Running After A While - Compression Issue

Are you still wondering about this question: why my lawn mower stops running after a while? When your lawn mower doesn’t have any of the issues mentioned above, it might have a compression problem.

Under this situation, the mower gets hot, a slight change occurs in the valve’s shape and reduces the engine’s efficiency.

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Not everyone can figure out this issue because you need professional knowledge to find out the compression issue.

So, these are all the possible reasons when you want to know why my lawn mower stops running after a while.

How Do You Fix A Lawn Mower That Won’t Stay Running?

Fixing a lawn mower is essential to ensure optimum performance while cutting the grass. You can’t use a lawn mower that often stops while cutting.

So, you have already known what would cause a mower to start but not stay running. Now, let’s find the answer to this question: how do you fix a lawn mower that won’t stay running.

Here one thing you should remember that different lawn mower has different issues. So solutions will be varied based on the problem. That’s why we are going to disclose all possible solutions on what would cause a mower to start but not stay running.

Fixing Carburetor Issue

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You have already learned that carburetor may become dirty or clog up. In order to deal with the dirty carburetor, you can use a carburetor cleaner such as WD-40 for super cleaning.

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First of all, unscrew the carburetor bowl and then clean each part of it by spraying the solvent on the surface. After spraying the cleaner, use fabric to clean out dirt, grease, or any carbon contaminants.

Fixing Gasoline Issue

Mixing new gasoline with the old gasoline may make formula impure if the old gasoline has a larger quantity than new gasoline. So, you want to add fresh gasoline.

One of the best things you can do is buying a stabilizer to overcome the jamming up of the issue. You will find a wide range of stabilizers are available in the market. You can use the Star Tron Enzyme Fuel Treatment or a decent one you prefer.

Moreover, it will cost less than $10 while using it for up to 2 years. Finally, don’t forget to go through instructions to find the balance between the fuel and stabilizer in your mower.

Fixing Spark Plug Issue

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Spark plugs are a handy tool, which you will easily find in nearby hardware shops. If your lawn mower spark plug becomes excessively dirty, you can use a decent cleaner with a stiff brush to clean them. However, avoid using any shot-blasting cleaner as it can lead to serious health issues.

On the other hand, if a tangled heap of carbons appears on your mower’s spark plug, replacement may be a better option. They are low-price and easily accessible, and you shouldn’t struggle to replace a new one.

Most experts suggest replacing the spark plug for each season or at least after two seasons. It will ensure you are using a trouble-free lawn mower.

Fixing Excessive Oil Issue

When your lawn mower oil tank has excessive oil, you may face difficulty running it. In that case, the solution is hassle-free straightforward.

You just remove some oil from the tank using a siphon. One tip is to add oil gradually. Before overfilling the tank, check out the dipstick position and add oil slowly. If you fear overfilling it, avoid making it full.

Fixing Battery Powered Lawn mower

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Are you using a battery-powered lawn mower? In that case, you want to ensure sufficient charging while cutting the grass.

For long-lasting charge, you can use a smart charger. Plus, when you don’t use the mower for several months, remove the battery from the machine and keep it separately in a safe place.

Lawn mower Stops After A While: How To Know When To Hire A Professional?

Should I Fix it Myself, or Take it to a Technician?

We have already shared all the possible issues you may encounter on what would cause a mower to start but not stay running. Also, we included several solutions, and we are expecting you have solved the issue by trying each of them.

However, if you failed to deal with the issue, it is best to call for a professional. Some other possible problems could be a faulty choke, gas tank or gas line blockage, etc.

When the problems are too complicated, professionals are the best choice. Unless you are extremely handy, you may end up damaging another part instead of fixing them.

In addition, if your lawn mower has a warranty, don’t forget to seek the manufacturer’s help. After all, it will be cost-free, and you can relieve yourself of mess.

On the contrary, if there is no warranty left for the mower, contact a nearby local shop that is popular in the area. Tell them everything about the kind of problems you are facing.

How To Prevent Lawn Mower Issues?

How To Prevent Lawn Mower Issues?

You have already learned why my lawn mower stops running after a while and what the possible solutions you can apply are.

Though engines are supposed to show issues after a specific time, you still want to take care of them appropriately to delay the problems.

The following tips will help you avoid lawn mower issues.

  1. Use a carburetor cleaner spray to keep your carburetor clean and efficient.
  2. You can use an engine degreaser because cleaning your engine will be easier with it.
  3. The oil tank should not be overloaded. You can use a dipstick to eliminate the issue.
  4. Don’t forget to clean the air filter regularly to prevent blockage issues.
  5. Changing lawn mower spark plugs after each season or at least after two seasons is a better follow-up.
  6. Make sure the gasoline and oil inside the tank are not too old and dirty. Using a stabilizer is a better option to keep gas fresh.
  7. Always keep the lawn mower engine clean after cutting the grass. It will prevent grease and dirt build-up.
  8. Make sure no screws or nuts are loose for any parts of the mower.
  9. It is best not to cut wet grass as it may cause clogged issues.
  10. As per your cutting frequency, it is better to sharpen the blades for smooth cutting.

Systematize Your Work

Before following a particular solution, you want first to figure out why my lawn mower stops running after a while. If you failed to figure out the type of issues you are having, you might follow the wrong solution.

Nevertheless, you are free to try each solution to remove the issues though it is time-consuming. In that case, apply the simple and straightforward solutions first and then go to complex ones.

You first want to tell yourself whether you are comfortable handling the situation of your own. As the procedure can be complicated, you may not be familiar with the basics. In that case, taking professional help is a better option to save time, effort, and hassles.

Never Run Your Mower Without The Blade

Never Run Your Mower Without The Blade

One of the most common mistakes many gardeners made is starting the mower without the blade. Aluminum flywheels are mainly used for lawn mowers, and the extra blade weight is part of the system that powers the flywheels.

As you know the basics of how a lawn mower works, the system will experience an increase in inertia due to this.

You will face difficulty starting the machine without blades due to a lack of spin momentum when switching on the machine.

Follow The Instruction Manual

Different lawn mower functions differently. You may need to follow a different method to take care of your mower.

In that case, following the instructions provided by the manufacturer is the best way to proceed. The more you stick to their guidelines, the better lifespan for the machine you can ensure.

Try to avoid any actions which are asked to. Following wrong guidelines may damage the mower or reduce the efficiency of the machine.


It is not a trouble-free job to maintain your lawn mower. But when you regularly do the maintaining job, you can prevent frequent occurring issues.

Ensure you always wear hand gloves while working on the mower engine to keep your skin safe from oil and gas.

Remember, if you don’t have enough knowledge of what you are doing, you shouldn’t do it. Consider getting expert help to solve the problem. Doing it yourself may damage some essential systems or parts of the mower.

Hopefully, you have gotten the answer to this question: why my lawn mower stops running after a while?

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Last update on 2021-10-03 / Affiliate links / Images from Amazon Product Advertising API