Why Does My Lawn Mower Stalls When Cutting Grass?

Lawn mower stalls when cutting grass

There are a number of reasons that a lawn mower may stall while it is being used to cut grass. The best way to approach the problem is to consider the least expensive and complicated fixes first. This route of troubleshooting can save you a great deal of time and money. Here you will learn about the most common causes of this problem that may be able to help you to avoid having to have it fixed by a professional.

Common Reasons Why a Lawn Mower Stalls When Cutting Grass

1. Being Overworked

One of the most common reasons that a lawn mower might stall while it is cutting grass is that it is being overworked. This is a mechanism that is intentionally incorporated into the mower to prevent the motor from being blown.

2. Grass is Tall or Dense

One reason that it might be overworked is that the grass is either too tall or it is extremely dense. This can make the motor work exceptionally hard in an attempt to cut through it.


One way to help to reduce the stress on the motor is to lift the mower before working on a new area and then slowly lowering it onto the next spot. This can be time-consuming, but it is the best way to address the issue. If the mower is able to continue working when taking this approach it will be clear that is the problem.

This most often occurs during the beginning of the mowing season or when an area has not received attention in a longer time period than normal. If the grass is more than a few inches high it may be better to use a weed wacker before attempting to mow the area.

3. Grass is Wet

Another problem that can make it difficult for the mower to put out enough power is if the grass is wet. When grass is wet it becomes much heavier than it is otherwise. It also tends to stick to the blades and the underside of the mower, adding additional stress to the motor.

Take a minute and check the underside of the mower. If there is a significant build-up of grass this is likely your problem.


The best approach is simply to wait until the grass has dried before attempting to mow the area. If for some reason you can not wait until it dries then you should do small areas and then turn off the mower and clean out the build-up that is present and repeat the process.

Lawn mower stalls when cutting grass

4. Low Fuel

The next area to check is your fuel. A lawn mower can start and run in idle with very little gas in the tank. However, when it comes time to run at full throttle it can stall.

Check your gas tank and see how much gas you have. If it is not full enough for you to see the gas you should put in a liter. You do not want to fill it in case you have a different issue that will require the fuel to be drained. If that does not resolve the problem then you will have to consider a new problem.

5. Issue With Fuel Line

If you still can not get your mower to run as you should you should consider whether or not there is an issue with your fuel line. If you do not have experience working with fuel lines it is probably best to seek the help of a professional. There could be build up in the line that is causing there to not be enough fuel in the engine to run at full throttle.

There could also be a small leak that is causing the problem. By having a professional investigate the issue it will save you time and money in the end as they can identify the problem quickly, reducing the chances of buying parts that weren’t needed.

6. Dirty Air Filter

A common problem is also the airflow that is reaching the engine. Almost every lawn mower has an air filter that permits air to enter the engine while ensuring that it is cleaned of dirt and debris before it does so. In most cases, this is located at the top of the mower, over the engine. It is typically encased with either a metal or plastic shroud that allows for venting. The air filter itself is typically easily able to be purchased at local hardware stores as they are a common item.


Simply remove the shroud and the air filter. They usually are able to be easily removed. You likely will be able to see whether or not the filter is dirty. You can then replace the filter with the new one that you purchased and replace the shroud. If this still does not remedy the problem then it may be time to seek the help of a professional.

In Conclusion

A lawn mower is a very simple engine, which is easy to fix if you have the right amount of experience. However, if you are not skilled in working on engines and do not fully understand how they work, trying to do technical fixes can lead to causing more problems instead of getting to the root of the problem. Above were the most common and basic things that can cause an engine to die when attempting to mow. If these do not work you should seek out the advice of someone that has experience fixing them.

Many people assume that this type of service is really expensive, but that really is not the case. Due to the fact that the engine is rather small and basic, those that have the knowledge to fix them can usually do so in a very short amount of time. This means that they do not have to charge a great deal for the labor. The parts are also typically rather inexpensive, and those savings are passed on to you.

By having professionals take care of the repairs you will actually save yourself money in the end. The last thing you want is to try to fix it yourself only to cause a new problem instead of fixing the one that already exists.