Troubleshooting Lawnmower Fuel Lines
Fuel Line Repair
A big part of keeping your lawnmower engine running smoothly is making sure that its carburetor and fuel linkage system are as clean as possible. Considering all the harsh debris that flies around a lawn mower while it's in action, that's no small feat. If your lawnmower engine doesn't start easily or performs poorly while running, it may have problems with its fuel delivery system and need repair.
Lawn Mower Fuel Line Repair
Remove the air cleaner and inspect the choke plate that's mounted on a shaft at the opening of the carburetor's throat. Make sure the choke plate closes easily and moves freely and is free of debris, as a sticky choke plate will make it hard for the engine to start. Use a spray carburetor/choke cleaner to clean the choke plate so that it moves freely.
- If your lawnmower is equipped with a fuel valve at the base of the fuel tank, turn it to the "off" position. Remove the fuel line from the tank and inspect the line to see if it is clogged. If necessary, clean the fuel line; then reattach it and return the fuel valve to the full "on" position.
- If your lawnmower is equipped with a fuel pump, make sure that it's operating properly. Shut down the fuel supply to the pump by either clamping off the fuel line or turning off the fuel valve (if so equipped). Remove the fuel pump and look for hairline cracks in its housing. If you find any, replace the entire unit. If the pump's internal parts are worn or brittle, rebuild the fuel pump using an original manufacturer's repair kit.
- Remove and inspect the spark plug. A wet plug may indicate a malfunction in the lawnmower's choke system, water in the fuel, or an excessively rich fuel mixture. A dry plug may indicate a leaking carburetor mounting gasket or a stuck or clogged carburetor inlet needle.
- While the spark plug is removed, pour a teaspoon of fuel into the spark plug hole. Reinstall the spark plug and attempt to start the engine. If it fires only a few times and then quits, then the carburetor most likely will need to be removed and rebuilt.
While sometimes the carburetor itself needs to be taken apart and thoroughly cleaned, the problem can often be identified and in some cases remedied by following these basic quick steps. But if these basic inspection steps do not resolve the problem, have your lawnmower looked over by a reputable service provider, who will be able to solve more complex small engine issues.