Motorcycle fuel leaks: Common causes & fixes

By Allstate

Last updated: January 1

Motorcycle gas leaks can be dangerous, and it's important to know where they're coming from. It's always best to consult a professional if you can. But if you're on the road, it might not be an immediate option. That said, here's how to identify where the leak is coming from and how to address it according to Motorcycle Habit.

count on quality coverage

Get the protection you need and the peace of mind you deserve with Allstate insurance.

The fuel petcock and fuel lines

According to Motorcycle Habit, the most common place for a motorcycle leak is the fuel petcock (aka the fuel valve). The fuel petcock is designed to shut off the supply of gasoline from the tank, explains Randakk's. It has an ON, OFF and RESERVE setting. Before you do anything, turn it to the OFF position.

First, check for leakage around the petcock itself, says Motorcycle Habit. If it's leaking from the bottom, the hose clamp may need to be tightened.

No leakage around the petcock might mean the gasket that connects the petcock to the tank is worn. One of the main functions of the gasket, explains Sun Auto Service, is to prevent leaks. For this reason, a worn gasket, says Motorcycle Habit, should be replaced. To replace the gasket, Motorcycle Habit recommends first draining the gas tank completely into a safe container via the following steps:

  • Disconnect the petcock's hose from the carburetor and place the hose into the container. That's where the gas will go.
  • Turn the valve to the ON position and let gas flow into the container.

Once the gas tank is empty, disconnect the petcock valve from the tank. Again, the gasket connects the petcock and the tank.

According to Motorcycle Habit, a replacement gasket is only a few dollars at an auto store or online.

The carburetor

The second most common motorcycle fuel leak has to do with the carburetor, says Motorcycle Habit. It also involves a gasket issue.

Universal Technology Institute explains that a carburetor sends a mixture of air and fuel to the internal combustion engine by way of the intake valve. A carburetor has a bowl that another gasket sits on. The bowl holds the gas.

According to Motorcycle Habit, the bowl may leak if the gasket is old and no longer sealing properly. Again, the gasket would need to be replaced. For this reason, Motorcycle & Powersports News recommends regularly replacing seals and gaskets.

Check the tank for holes

A hole in the motorcycle's fuel tank can cause gas to leak everywhere. Holes in gas tanks can form due to rust or wear and tear, explains Motorcycle Habit. Humidity can also increase the chances of holes forming. Don't weld or use a filler on the tank, warns Motorcycle Habit, as it may cause an explosion. Call a motorcycle professional to have it replaced.

The fuel injector

A fuel injector, explains Cycle World, is a computer system that governs the ratio of airflow and fuel going into the engine. It's the least common reason for motorcycle leaks, according to Motorcycle Habit, but it can still happen. The fuel injector is typically found in the back of the engine. Take it to a mechanic if it's leaking.

Are fuel leaks covered by insurance?

Collision coverage may help pay for certain repairs and replacement if a leak is caused by a covered accident or covered loss. Comprehensive may likewise cover motorcycle repairs for non-collision incidents like vandalism, theft and flooding.

If a leak springs from a worn part, however, it most likely won't be covered by motorcycle insurance. Wear and tear is considered a maintenance issue and you have to foot the bill. That's why regular upkeep is so important. Watch out for any leaks and be sure to address them immediately. If you're not sure what is and isn't covered, call your insurer.