Fuel lines on lawn mowers powered by gasoline engines will clog with debris after a certain amount of use. Frequently, sediment will accumulate at the bottom of the fuel tank and will flow into the rubber fuel line. Over time, the sediment will harden and clog the pathway for the fuel. When this occurs, the only remedy is to remove the fuel line. In many cases, if the fuel line is not cracked or damaged, it can be cleaned and reinstalled on the fuel system of a lawn mower.
Remove the top filling cap from the mower's fuel tank. Insert the hand siphon pump into the fuel tank. Run the other end into the gasoline container. Pump the bulb. Drain all fuel into the gasoline container.
Press the spring clamp that secures the fuel line to the bottom of the fuel tank, using the jaws of the pliers. Move the spring two inches onto the rubber fuel line. Pull the fuel line from the mower's fuel tank. Some gasoline may leak from the line.
Trace the fuel line to the engine carburetor. There will be a fuel filter installed somewhere along the fuel line. Remove the fuel line from the carburetor by pressing the spring clamp with the pliers. Move the clamp back two inches onto the fuel line. Pull the fuel line from the mower engine.
Remove the fuel filter from the fuel line in the same fashion as outlined in Step 3--there are two clamps, one on each end of the filter, holding the filter housing to the rubber fuel line hose. Discard the fuel filter.
Insert the nozzle of a compressed air source into the fuel line. Apply pressure. Blow the debris from the line. You may have to press on the rubber fuel line to break the hardended debris free. Keep applying air pressure until the line is clear of any obstruction.
Perform the same task outlined in Step 5 to all sections of the rubber fuel line. If no compressed air is available, you can use canned-pressurized carburetor cleaner. You will have to press on the rubber hose to work any hardened material free, while spraying the cleaner inside the hose. Wash all debris from the fuel line.
Install the new fuel filter into the fuel line at the same position. Attach the fuel line to the mower engine in the opposite order of the removal process.
Fill the tank with fresh gasoline. Start the mower engine following the on-board instructions printed on the mower housing.