A clean fuel filter strains the fuel before it reaches the carburetor and prevents foreign particles from clogging your engine. A dirty fuel filter can make the engine run too lean, with diminished performance and uneven operation. Other factors can cause these problems, but the fuel supply is one of the easiest to check.

Some filters are located inside the tank, others are fitted into the fuel line between the tank and the fuel pump. Most use either a mesh screen or pleated paper. The size of the holes in the filter will determine the largest particles that can get through the filter, and the number of holes will affect the amount of fuel that can flow through the filter.

Filters contain either a mesh screen or a pleated-paper element, and are rated by the size of the holes in the filtering material, expressed in microns.

Inspecting A Fuel Filter
Wear safety eyewear whenever removing or inspecting a filter to protect our eyes from liquid fuel or fuel vapors. Have a dry cloth handy to hold the filter and catch and dripping fuel. If the filter is installed inside the tank, you will need to drain the tank before you can remove the filter for inspection or replacement.

1. Shut the fuel valve, if equipped. It's located at the base of the fuel tank, where the fuel line is attached. If your tank is not equipped with a fuel valve, clamp the fuel line, using a fuel line clamp.

2. If your filter is installed in the fuel line, remove the metal clips on each side of the filter, using needlenose pliers, and slide the filter out of the fuel line.

3. Shake the filter over a clean cloth to displace any remaining fuel, then use the cloth to wipe away any residue from the outside of the filter.

4. Keep the filter a safe distance from your face and look through one end. You should be able to see light shining through clearly from the other side. If debris is clogging the mesh screen or pleated paper or the inside of the casing, replace the filter.