Determining the size of a fuel line in a vehicle or motorcycle is important prior to replacing it. The fuel line, along with the other parts of a fuel system, are responsible for delivering the fuel from the fuel cell into the carburetor. It is important to have the right size so the vehicle operates efficiently. The size of the fuel line is determined by the outside diameter. Completing the measurement is simple and takes relatively few tools. The same steps can be used to measure other types of tubing, such as those for brake lines.
Uncover the fuel line so that it is visible and can be reached easily. Do not remove the fuel line or disconnect it.