Why Does My Lawn Mower Stops Running When Hot

If you’ve ever dealt with a lawn mower that stops running when it gets hot, you know how frustrating it can be. After all, what’s the point of having a lawn mower if it can’t handle the heat?

There are a few reasons why your lawn mower might stop running when it gets hot. The most common reason is that the engine isn’t getting enough air. When the engine gets hot, it needs more air to cool down. If the air filter is dirty or clogged, the engine won’t get enough air and it will shut down.

Reasons Why Lawn Mower Stops Running When Hot

Gas Oil Problems

Well, there are lots of reasons behind getting the lawn mower hot and as a result, it gets stopped. Among them, the gas oil problem is a remarkable one. What actually happens is the problem between the supply of lubricant and fuel. As a consequence, the engine starts getting heated and it shut down.

That’s why you have to check the fuel supply very often. Better give the fuel a check before each use. Without it, it is recommended to dump out your lawn mower gas which is aged more than 30 days. Because the gas age of more than 30 days will get wicked. The gas will clog up the fuel system with a sticky element.

So, if you use old gas and face this kind of problem, you have to clean the fuel tank in a good manner. Without it, you have to replace the fuel hoses and fuel filters. There are some other things where you need to pay heed like you have to add the oil if needed, you have to change your lawn mower oil after operating every 25 hours.

Vapor Lock

Vapor lock is a problem that is overlooked often. It actually likes a trigger for an engine. The engine gets stopped when the heated gases are unable to vent inside of the fuel tank. This pressure bounds the gas flow to move and reverse out of the carburetor which leads the engine to shut down. The engine can’t work with this kind of heated gas staying inside of the tank.

The vapor lock in your lawn mower happens because of a dirty fuel tank cap. You will see that your caps hold a small vent hole that lets the tank maintaining the pressure properly. In this case, you need to replace or clean the fuel cap.


When the engine is unable to vent heated gasses it gets from the inside burning or the engine takes cool air for the next burning stage, your lawn mower gets stopped. Generally, the air comes and goes through the filter and muffler. That’s why the filter gets dirty. So, you have to go through the filter cleaning procedure every eight operating hours.

Without it, you have to clean the muffler every sixty operating hours. You should replace the air filter or muffler if you find it is very dirty.


Apart from the gas oil problem, there is a lot that happens in the carburetor. The carburetor leaves a gummy deposit whenever the old gas passes through it. This deposited gummy builds in the hoses within the carburetor. As a result, you will face problems like the fuel will choke off while reaching the carburetor.

Again, if your carburetor doesn’t get adequate gas, then the engine will shut down. So, you are supposed to understand that because of the problem in the carburetor like sticking an intake needle will work as an obstacle to the fuel.

Here, what can you do is removing the carburetor, disassembling and then cleaning it completely. You are recommended to install the carb kit before you go to install the carburetor again.

Lawn mower stops running when hot

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