Why is My Dirt Bike Leaking Gas: Reasons and Solutions

why is my dirt bike leaking gas
why is my dirt bike leaking gas

Why is My Dirt Bike Leaking Gas – Dirt bike maintenance is vital in avoiding any issues with your bike. If you are not careful, you can face problems like a backfiring bike or even a smoking one. Other times, you may need to replace parts like the chain or tire. Maintenance in general comes with many questions you need to be prepared to have answers ready. One such question is “why my dirt bike is leaking gas.” Gas leakage is not something uncommon in dirt bikes, but it is something you’ll want to fix quickly in order to prevent future problems.

Generally, when fixing a gas leak, you should start by turning off the fuel, drying any wet parts, and then turning the fuel back on. If there’s a big leak, you’ll see fuel gushing out. For slower leaks, watch for gas drops at the overflow or carburetor base, and follow them to find the source of the leak before making repairs.

Reasons and Solutions

Like many dirt bike issues, many reasons can lead to gas leakage and different solutions to fix it:

Carburettor Overflow

If you see gas leaking from the carburetor’s overflow, it might be due to a stuck float valve caused by dirt or debris. This valve is connected to a float inside the carburetor that manages fuel levels. If the float valve is disconnected, it can lead to fuel leaks. To fix this issue, take off the carburetor and float bowl. Cleaning the float bowl is optional but can help if obstructions are preventing the valve from closing properly.

Fuel Leakage From The Float Bowl

Gas leaks on a dirt bike can slowly develop from the float bowl, but they’re not easy to spot. To fix this, you might need to take your time because these leaks don’t show up visibly and often make the area wet and oily. You can access the float bowl by turning a screw or removing the carburetor. Once you’ve done that, check the gasket and carburetor housing for grime and roughness, which indicates a worn gasket that you should replace. Learning how to detach and reattach these parts is a useful skill.

Many dirt bikes include a carburetor rebuild kit, and you can easily replace the floating bowl by removing and reinstalling the original. Sometimes, the four screws holding the float bowl on a gasket carburetor might loosen for no apparent reason, but putting in a new gasket and tightening those screws will solve the problem.

Carburetor Drain Screw

Dirt bike carburetors typically have a drain to catch any fuel leaks, but sometimes, these drains can cause gas leaks, especially if the bike hasn’t been refueled recently. To fix this, you can replace the gasket that seals the drain screw to the float bowl. Repair kits are available in physical stores and online, some even include an extra drain screw. 4

It’s important to know that not all carburetors have a drain screw. In those cases, you should replace or patch the gasket if you see a prominent head. If the problem continues, check the fuel line between the carburetor and the fuel valve for proper installation and any leaks. Over time, the fuel line can deteriorate. Especially if it’s exposed to ethanol-containing gasoline. In such situations, it’s a good idea to keep spare fuel lines on hand.

Fuel Shutoff Valve Leaking Fuel

Most dirt bikes have a fuel shutoff valve located near the gas tank. You can trace your fuel feed hose back to find it. These valves serve to control the flow of fuel during storage, transportation, and riding, with some featuring a RES setting for extra fuel.

If the fuel valve starts leaking, the best course of action is usually to rebuild it. You can find readily available rebuild kits online. Rather than attempting to pinpoint the specific rubber component causing the leak, it’s often more practical to rebuild the entire valve for a comprehensive fix.

Fuel Line Issues

If nothing else works, check the fuel line between the carburetor and the fuel valve. Make sure the connections are tight with hose clamps. If the fuel line is old and worn, it’s a good idea to replace it because ethanol in today’s gas can cause it to deteriorate. Replacing the fuel line is easy and doesn’t cost much. Remove the old one and go to a local auto store to get a new piece that matches the old one’s size and length. For carbureted bikes, you don’t need an expensive high-pressure fuel line; a low-pressure one works just fine and is much cheaper.


While there are many reasons and solutions to the question “why is my dirt bike leaking gas?” you should be aware of what skill you have when working on your bike. If you are fairly new to dirt bikes, you may want to lessen any risk of messing with your dirt bike by checking with a professional first. Learning dirt bike maintenance means many things. This includes dealing with things like low compression, overheating, flooding, and bogging. Aside from this, it can help to learn about tools like cleaners and oils. Through learning these things, you can avoid things like fueling the wrong gas.

You might also enjoy