What to Do When the Lawnmower Keeps Dying

Lawnmower troubleshooting

Technology has undoubtedly made our lives a lot easier. But that doesn’t mean it doesn’t provide its fair share of frustrations, such as when the lawnmower keeps dying. 

There are few things as exasperating as being in the mood to tackle lawn care, only to find the lawnmower stalls when cutting grass. Some people even find that their lawnmower starts then dies, only to show no further signs of life.

In most cases, a lack of maintenance is to blame. We expect to be able to pull the cord and have our outdoor equipment roar to life. That’s rarely the case, especially if it has been tucked away in your tool shed over the winter months.

Rather than admit defeat immediately, it’s worth trying to find the answer to your burning question: why does my lawnmower only run for a few seconds then dies? It could be any of the following reasons.

Your carburettor is clogged

My what is clogged? There may be a lot you don’t know about your lawnmower, and that’s okay. The more you use your lawnmower, the more you get to understand what it’s made of. You will find that most, if not all, small gas-powered motors contain a carburettor. Its job is to mix a specific ratio of gas and air together to ensure your mower runs right.

When you leave fuel in your lawnmower for an extended period, some components of the fuel can evaporate. What’s often left behind is a sticky, thick, and even gummy substance. So, when you notice that your lawnmower stalls when cutting grass, or it starts then dies, this might be the issue.

You give your lawnmower enough gas from the primer bulb or choke to start, but then the blockage starves the engine of gas, and it cuts out. You may be able to clean the carburettor with a specific cleaning fluid, or a full carburettor replacement may be required.

In the future, consider investing in a gas stabiliser to keep your fuel fresh. Then, the next time you go to use your mower after a hiatus, you’re unlikely to face the problem of your lawnmower continuously dying.

The fuel cap vent is clogged

If your lawnmower keeps dying, the carburettor is always the first part to check. But it’s not always the cause of the problem. If your lawnmower starts then dies, a blockage in the fuel cap vent is also a possible problem.

Before you start mowing your lawns, you probably fill up the fuel tank. Then, as your engine consumes the fuel, it gets lower. To combat this, most mowers have a small vent in the cap that lets air enter it. If this becomes blocked, air can’t get into the tank, and you can experience a vapour lock.

A vapour lock can prevent fuel from being able to flow to your carburettor. Your mower then stalls when cutting grass. There is a quick and easy way to determine if this is the problem. Loosen the cap slightly, then try starting the engine. If it starts with no issues, you may need to replace your fuel cap.

Your petrol is bad or old

One of the first things to do when buying a new lawnmower is to read the user manual. It’s not the most riveting of novels, but it can stop you from making grave errors when it comes to lawnmower care and maintenance.

For example, some mowers function better with different fuels. There are even fuel types available at your local petrol stations that damage carburettors. Only ever use the fuel recommended by your mower manufacturer. 

Still, even using the appropriate fuel doesn’t mean you won’t strike any problems. For example, if your lawnmower keeps dying, then your fuel may be old. Old and bad fuel can lead to a gum residue in your carburettor. 

You can prevent this from becoming a problem by emptying the tank of fuel before storing it for long periods. Alternatively, add a fuel stabiliser product.

The spark plugs are worn or damaged

Spark plugs in a lawnmower may only be a small part, but they have a huge impact on how your machine runs. If you find that your lawnmower keeps dying, or keeps stalling while cutting grass, then inspect the spark plugs.

Look for signs of damage or wear. Something as simple as a cracked porcelain insulator can mean an electrode has been damaged or burned away. If you discover heavy carbon buildup as well, then it’s time to replace them.

If you have a spark plug tester floating around your garage, then put it to good use. Test it to see if it’s defective or still working. When the engine is cranking, you should notice a spark between the terminals to show that it’s in good working order. If you don’t see a flash, the spark plug is defective.

Is it time to call in the experts?

Lawnmower maintenance can be hard work. Sometimes, it can even feel like you spend more time maintaining the mower than the lawns! Therefore, you may see the value of hiring a lawn care company to assist. Rather than worry about carburettors, fuel stabilisers, and spark plugs, all you have to worry about is how you’ll spend your free time. Get in touch with a trusted lawn care expert today.

Klaris Chua-Pineda