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Gas lawn mower won't start? Here's how to fix it

Gas lawn mower won't start
(Image credit: Getty Images)

When your gas lawn mower won’t start, it can be a real inconvenience. The best gas lawn mowers (opens in new tab) are famed for their precise cut, their hefty mowing power and their quick mow time. But when your mower won’t turn on, cutting your lawn can prove tricky.

Many of the top-rated gas lawn mowers can last around 10 years, and in some cases even longer.  So if your lawn mower has stopped working within this time frame, it could be down to a few reasons. From a faulty flywheel to an empty gas tank, there’s a range of factors why your mower won’t start.

To help you get to the bottom of why your gas lawn mower won’t start – and how to fix it – we’ve roped in the help of expert Kingsley Onyemali from Taskrabbit (opens in new tab). Keep reading to find out everything you need to know about getting your lawn mower back to its best.

Reasons why your gas lawn mower won't start

1.  The flywheel isn’t working

One of the number one reasons why your gas lawn mower won’t work is because of a faulty or broken start cord or return spring.

Kingsley says: “This could be as a result of normal wear and tear that affects almost all things as a result of frequent usage. Several issues can happen inside the flywheel, like break cord, worn out return spring, broken fan blades and more.

“It is important to observe that the starter cord coils back in after dragging it. Not recoiling means something is faulty inside the flywheel. Most times you’d need some special tools to replace any faulty part inside this chamber, especially if the recoil spring is broken.”

2.   It’s the air filter

Unfortunately, when it comes to gas lawn mowers, dirt, oil and even grass can clog the air filter. But what impact does this have on the gas lawn mower? 

As Kingsley explains, it can cause: “The machine to operate on a low power or not even start at all.”

The best way to fix it? According to Kingsley: “It’s ideal to change the air filter frequently depending on how often it is used.”

It can be frustrating when your gas lawn mower won't start, but there might be an easy fix…

It can be frustrating when your gas lawn mower won't start, but there might be an easy fix… (Image credit: Getty Images)

3.  The spark plug is to blame

“This is a very small, but powerful, part of the lawn mower as it creates the sparks that ignites the engine itself,” Kingsley says. “Frequent uses can cause the spark plug to lose its cell power.”

According to Kingsley, sometimes if oil and dirt builds up on the top of the plug, it may create a barrier that stops the sparks from igniting the engine.

“You can almost tell when the lawn mower is having a dead spark plug because it seems like it wants to start but it wouldn’t start,” he says. “Sometimes it helps to check if the fuel gauge is open whenever the lawn mower seems like it’s about to start but not starting.”

4.  Blame it on the engine oil

Like any other vehicle, be it a car or van, looking after your engine oil is a necessity. 

Kingsley says: “The engine oil needs to be checked from time to time to ensure it isn’t too low or too much – it must be within the gauge and must be clean. And like vehicles, the oil has to be changed when it loses its potency.”

5.  An empty gas tank could be to blame

This can happen to the best of us. But making sure your gas doesn’t run low, and it’s changed regularly can make all the difference when it comes to looking after your mower.

As Kingsley says: “Even when you are diligent about keeping the gas tank full, it is important to check for leakage and ensure to always shut off the fuel gauge after every use.”

Generally speaking, it’s thought that the shelf life of gasoline with ethanol is about one month while ethanol-free gasoline has a shelf life of around three months. If you’re wondering how to put gas in your lawn mower, check out our handy guide.

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Becks is a freelance lifestyle writer who has worked extensively for Top Ten Reviews during the past year. She started her career in print journalism at a local newspaper and has since then worked across digital and social media for food titles and home interior magazines. When she’s not writing, she’s reading and when she’s not reading, she’s writing. 


With contributions from