Any time that old gasoline is left to sit, dry or evaporate inside a fuel tank, there is a good chance that the carburetor will get gummed up. The gum is a residue produced by old, drying or dried gasoline. It does not matter whether the carburetor is on a small engine -- on a mower, leaf blower or trimmer -- car engine or outboard boat engine. The end result is usually the same -- it will either prevent the engine from starting, or it will make the engine sputter or run poorly.
Hold the carburetor over a bucket and then remove the float-bowl drain screw at the bottom of the carburetor with the flathead screwdriver. The float-bowl drain is a small reservoir that catches any excess gasoline that may spray from the carburetor. Allow any excess gasoline trapped inside the carburetor or float bowl to drain into the bucket.
Scrape off the old float bowl gasket with a putty knife until all of the gasket has been removed.
Remove the choke-lever clip on the side of the carburetor with a pair of needle-nose pliers. Remove the choke screws with the screwdriver.
Remove the low-speed needle and the float from the carburetor with the screwdriver.
Remove the carburetor jets from the front of the carburetor with the screwdriver.
Fill the small container with gasoline and submerge the float, jets, high-speed needle and choke screws inside and allow them to soak.
Spray the outside of the carburetor with the spray cleaner and allow it to soak in for approximately one minute. Use the wire brush to scrub the outside of the carburetor
Spray carburetor cleaner into the open jet ports and the fuel-line ports. Scrub the inside of the ports with carburetor cleaner, removing all gum and buildup.
Remove the screws and jets from the gasoline and dry them off with a towel.
Towel off the outside of the carburetor and then allow it to air-dry for at least an hour.
Use the screwdriver to re-assemble the jets, float and high-speed needle and choke screws.
Place a new gasket between the float-bowl gasket and the body of the carburetor and then attach it to the carb with the retaining screw.
Replace the choke-lever clip and the choke screws with the screwdriver.
