What to do When Your Lawn Mower is Leaking Gas

What to Do When Your Lawn Mower Is Leaking Gas

It’s common for a lawnmower to have gas leaks during its lifetime. However, this can be incredibly frustrating as a lawnmower owner, especially when you see fuel puddles on your lawn or when you keep smelling the pungent odor that gasoline usually has.

But you don’t have to worry if your lawn mower is leaking gas. There are practical solutions to correct this issue. In this article, we will explain how to know when your Lawnmower begins to leak gas, the causes, and the solutions. Let’s get into it.

How to Know Your Lawn Mower is Leaking Gas?

There are ways to know when your lawn mower starts leaking gas. One of them is the gas smell whenever you use your lawn mower. This is a sure sign that your Lawnmower is experiencing a gas leak and needs immediate attention. 

Another way to know your lawn mower is leaking gas is to spot dead grasses in your yard after mowing your lawn. This is because gasoline will kill the grass it drips on. Looking for tiny patterns of dead grass after you cut your property will help you to know whether your Lawnmower has a gas leak.
One more effective way to know when your Lawnmower starts leaking is to park it overnight on a piece of cardboard. This is even more effective because you will confirm that your Lawnmower is leaking gas and know the areas from which the gas is leaking.

Reasons Why a Lawnmower Leaks Gas and Quick Solutions

There are several reasons why a lawnmower leaks gas. This section will highlight five causes why your Lawnmower leaks gas and how to resolve these issues.

Fuel Filter

When you notice your lawn mower leaks gas, you should check its fuel filter. This is especially crucial if you haven’t changed it in a while. Plastic inline fuel filters start to break down and become soft and weak after holding gasoline.
It should also not be a surprise if you remove the fuel filter and crush its ends. This is usually because the fuel filter has become soft or melted. The primary reason why this happens is because of bad gasoline. However, this can also occur if you haven’t changed your fuel filter in a while.

How to fix it: After you have removed the bad fuel filter, replace it with a new one. This should stop the leaks. Also, we advise you to use recreation fuel for your lawnmowers instead. It is more friendly to your fuel filter.

Fuel Filter

Another reason your lawn mower is leaking gas is that its fuel tank is damaged. Whenever an accident with a lawnmower happens, the fuel tank usually cracks. These include hitting the fuel tank against a low-hanging shrub or something falling on the tank.

Fuel tanks also leak when there is rust. This is usually the case if your lawn mower is old. To confirm this, check for rust holes in your fuel tanks. Furthermore, if you have a plastic fuel tank on your lawn mower, the seams where the plastic is molded together might have separated, leading to a gas leak. You can also check the seams to confirm.

How to fix it: Replacing your fuel tank solely depends on its design. While some tanks are easy to remove because they are separate pieces, others are under the engine shroud, making them very difficult to remove and replace.

It doesn’t matter where your Lawnmower’s fuel tank is located; the first thing to do is to drain the gasoline in it. If your fuel tank is a separate piece, you must remove the fuel line from the tank and dismount it from your Lawnmower.
If your fuel tank is located under the engine shroud, the first step is to remove the shroud. You must not forget that some models require that you first remove the starter assembly. After this, remove the fuel line and dismount your fuel tank.
After removing your fuel tank, replace it with a new one, and you are good to go. This repair is simple and cost-effective.


One of the first places to look at when your lawn mower is leaking gas is the carburetor—this function as a storage for gasoline after leaving the fuel tank. The bottom area of the carburetor, the bowl, is the first place to look when checking for leaks. A thin O-ring extends between the bowl and the base of the carburetor. This thin O-ring resembles a rubber bank.

It is one of the familiar places that gas leaks from because it is near the engine’s heat. This area becomes heated when you use your Lawnmower and cools when you shut it off. This makes the o-ring go from hot to cold temperature constantly. The stress from this process makes the ring hard, thereby losing sealing strength.
How to fix it: Removing and replacing the O-ring gasket is straightforward. You must get your lawn mower’s model, make, and spec number and take it to a local dealer. This information will help the dealer to give you the appropriate O-ring gasket for your Lawnmower.
After getting the correct O-ring, unscrew your carburetor and drop the bowl. Carefully replace the O-ring gasket and install the bowl. The gas leaks should stop immediately after doing this

Fuel Lines

Another place to check when your lawn mower leaks gas is the fuel lines. When a fuel line is damaged, it might start leaking gas. The reason why most fuel lines get damaged is because of aging. Generally, fuel lines begin to harden and eventually break or crack as they age.

 Fuel lines don’t make a tight seal around the carburetors’ fittings, fuel tanks, and filters when they harden. This can result in gas leaks. A lawnmower’s fuel line is usually exposed. So, finding the areas where gas is leaking is easy and replacing them is straightforward. Before repairing the faulty fuel line, you must drain the gasoline left in the fuel tank. 

How to fix it: Use a plier to remove the clamp on the fuel line, then pull it from its fitting. If pulling it from the fitting doesn’t work, rotate the fuel line around its fitting. The line will slide out easily.
After you have removed the damaged fuel line, use it to measure the new fuel line you want to use. This is because it is better to use a similar length to get a good fitting. Finally, install the new fuel line and replace the clamp. You should lubricate the line to slide easily into its fitting.

Stuck Float

A stuck float might cause your lawn mower gas leak. Check the carburetor’s opening to confirm if you have a stuck float. The float could be stuck if you see any gas leak coming from the air intake port. The primary function of the float is to control how much fuel the bowl of the carburetor will hold. So, it turns the gasoline on and off from the fuel tank. The float will stop turning off the fuel tank if it gets stuck, leading to gas leaks.
How to fix it: When a float gets stuck, the best solution will be to completely open the carburetor to check what caused the float to get stuck. Depending on the cause of the float stuck, the carburetor might need to be cleaned, rebuilt, or even replaced.

Check out ultimate guide on maintaining your gas-powered lawn mower to prevent gas leaks.

Final Thoughts

Every lawn mower experiences issues and gas leaks are one of them. While this may seem difficult, it is repairable.

With this article, you understand when your lawn mower is leaking gas, the likely causes, and their solutions. So, whenever your lawn begins to leak gas, you can use the information provided to find where the leak is coming from and repair it yourself. 

Frequently Asked Questions

Why Do Gas Leak from The Primer Bulb?

Gas leaks from your Lawnmower’s primer bulb because it has split and is damaged. Mice usually cause this because they love to eat primer bulbs. All you have to do is remove the retaining ring of the primer bulb and install another one.