How to fix a lawnmower that won’t stay running, step by step

Approx Reading Time: 8 minutes

You are mowing your lawn, and suddenly your lawnmower stops. It may be a frustrating moment, but don’t worry. There can be many causes of why your lawnmower stops running. It can be an engine or a fuel problem. If you try to start the lawnmower and it does not start, this can be due to many similar causes. A dirty carburetor, a dirty air filter, malfunctioning spark plugs, or an insufficient gas flow to the engine. This article will help you quickly fix the problem.

How to fix a lawnmower that won’t stay running, step by step:

  • Step 1. Clean the spark plug.
  • Step 2. Clean the air filter.
  • Step 3. Ensure correct fuel supply.
  • Step 4. Tighten the mower blades.
  • Step 5. Check the carburetor working.
  • Step 6. Check the mower level.

Reasons why a lawnmower won’t stay running:

There are two common situations for your mower to not stay running. The first is that it starts for a period and then stops. The other is that it does not start at all. Both of these situations may have similar causes. The most common reasons why your mower does not stay running are:

  1. The dirty spark plugs of your lawnmower
  2. Dirty Air Filter
  3. Fuel not correctly reaching the engine.

These causes are similar if your lawnmower does not start. You need proper maintenance for your lawnmower to keep it running for an extended period. Proper maintenance will also make your lawnmower last much longer.

Luckily for you, a mower that won’t stay running is more an indication for smaller problems than a signal for a major problem. It means that your lawnmower needs maintenance. And almost all of this maintenance you can do easily at home.

Steps to fix a lawnmower that won’t stay running:

Although the lawnmower is a sturdy device, however, it may face technical difficulties too. It has to run through rough terrain most of its life. That can cause some essential level maintenance and performance issues such as unevenly cut grass. In this article, we will take you through the steps to troubleshoot the problem.

● Step 1: Check the spark plug:

Every gas-powered engine has a combustion chamber powered that is producing the required power. The spark plug ignites the fuel in the engine. However, the spark plug’s condition deteriorates over time. It may get clogged up with oil and fuel residuals. This can harm its performance. This can, in turn, lead to timed and uneven sparks by the device.

To solve this issue, using a feeler gauge, check the distance between the spark plug terminals. Compare it with the manual. If the difference between readings is not much, clean it; otherwise, replace it.

● Step 2: Check the air filter:

Every gas-powered engine consists of a carburetor that mixes the gas and air to make it more explosive. After it has passed through an air filter that removes dirt, insects, and debris from entering the chamber, the air comes in. If your lawnmower has a dirty air filter, it will face difficulties starting as it will be difficult for the air to reach the fuel for efficient combustion. So, in this case, you should keep the air filter of your mower clean by using a blower regularly. Replace it annually, too, to be on the safe side. Efficient combustion ensures smooth performance.

● Step 3: Ensure the correct fuel supply:

Sometimes, the fuel is not properly reaching the engine to start or shut off after a while. The easiest solution for this is that you check the carburetor and the fuel lines connecting it. Probably, some scaling in them or clogging due to low fuel quality is the cause. If proper fuel isn’t burned, the mower doesn’t generate enough power for smooth working. A rough working mower will not cut even.

The solution to this problem is cleaning all the fuel lines. Then, replace the old fuel with the newer one and add anticoagulant agents. Some anti-knocking agents will further enhance performance. At the very least, the missing and running problem is fixed.

● Step 4: Tighten the mower blades:

The unevenly cut grass can be a victim to the loosely fixed, shaking blades. The mower blades have to go through challenging terrains and grass. They loosen with time. By merely fixing them tightly with a screwdriver and plier can solve the issue. Also, check the quality of the mower blades. If they have worn out, either sharpen them (if they have the capacity) or replace them altogether.

● Step 5: Check the carburetor working:

The most crucial component of a gas-powered lawnmower is its carburetor. It is responsible for mixing adequate amounts of fuel and air. After you have gone through all the previous steps, and the mower still has the same issue, your carburetor is at fault. In case you have a worn-out carburetor, then prepare all things to clean the engine. Pinch the gas hose first with a clamp or a vice grip to stop the fuel from entering the carburetor. Always take care of safety precautions before starting repairing.

Thoroughly clean the mower carburetor with a cleaner spray or fuel-oil mixture. Then, dry all its insides. Use a blower to remove any moisture and clean all the pipelines too. Then, carefully tighten all the connections and seal it back. If it is too worn-out, replace the carburetor. However, please take it to an expert before.

● Step 6: Check the mower level:

The final step in all this procedure is the final alignment of the machine. After you have ensured that no other component is the cause behind the running problem, set the machine’s level back to normal. The level may get disturbed while opening and closing the parts. So, first, check the level of the base using a balancer (floater type). The air bubble should be in between. Next, check the amount of air in the tires. The tires should be balanced with the base so that the mower looks adequately aligned.

For a visual journey through the steps mentioned above, you can look at the following youtube video.

Frequently asked questions:

1. How to check the spark plug?

To check the spark plug, whether it is good or not, you will need to check the common signs of damage. First of all, unplug it and clean the area around the spark plug. Use a spark plug socket to unplug it. If the electrodes are burnt, you should change the spark plug at once; if it seems to be working, replace it, and avoid over-tightening. If the engine starts for a few seconds and then dies, then it means that the spark plug is okay, and there might be another problem.

2. Seeing a lighter colored smoke, what to do?

If you are looking that your lawnmower is smoking and the color of smoke is lighter and not allowing your mower to start, you need to call a professional. Because in this case, special tools and kits are required to repair it, and it cannot be done by your attempts if you are not that much skilled as a professional.

3. What to do if the problem stays even after the carburetor was cleaned?

Suppose the mower starts and then dies after a few minutes while you have already cleaned your carburetor. Then there must be a possibility that the oil reservoir is overfilled. If the smoke is coming out and the engine stalls, then these are the signs of overfilling. In this case, tilt the lawnmower up and hold it, making the oil circulate in all the engine parts. After some time, rerun the machine; if it runs for a more extended period, then the problem is excess oil. Catch some amount of oil from the lawnmower by using a pan.

Final Remarks:

In short, if you face this issue while mowing your lawn, don’t get frustrated and follow the solutions mentioned above. Hopefully, this will help you in solving your problems. If your machine is well maintained, then there is minimal possibility that you will face these issues. You should have an in-depth check on your lawnmower’s maintenance so that they can run properly for a more extended period without causing any issues. However, if you still have to face these issues, don’t worry because this article has all the possible solutions for your problems.

If the lawnmower has some severe issues like smoking very severely and is shutting off, again and again, you should call a professional. While repairing your lawnmower, always take care of safety precautions before doing anything. These machines are working devices that you need in your daily life to make your work easier. Sometimes, these machines need some treatment and care to work for you properly. Be ready to spend some hours on maintenance to make them last much longer.