Leaking motorcycle fuel tanks can be addressed by the do-it-yourselfer. There are many reasons for a motorcycle’s fuel tank to leak, including poor welding from the factory, rust, and damage sustained if the motorcycle is dropped or crashed, among other reasons. A leaky motorcycle fuel tank could cause a fire, and it can cause burns to the skin if the leaking fuel gets in contact with body parts. Leaking fuel can also stain or ruin clothing and gear.
Drain the fuel. Remove the fuel line from the fuel tank of the motorcycle and allow the fuel to drain into a suitable container. This is typically accomplished by using pliers to compress the wire hose retaining clamp and pulling the fuel line from the fuel tank nipple. Wipe up any spilled fuel with a clean rag.
Remove any rust. Pour paint thinner or acetone (one to two quarts) into the tank and add a handful of small nuts and bolts into the tank. Wrap the filler hole of your fuel tank with plastic wrap and secure this with a rubber band. Shake the fuel tank and rotate to ensure the thinner and nuts and bolts make contact with all points of the tank's interior surface. The nuts and bolts will aid in dislodging any rust from the inside of the tank and create small scratches for the epoxy to adhere to.
Replace the fuel tank. In the reverse order of the removal steps, install the fuel tank and fill with fuel. If there is still fuel leakage, take the tank to a reputable radiator shop and ask them to re-weld the tank. Many radiator repair shops also fix fuel tanks.