The fuel pump on a lawn mower is responsible for sending the fuel from the gas tank into the carburetor where it is needed to run the engine of the mower. When the fuel pump gets clogged or damaged, it will not allow fuel to get to the carburetor, preventing the engine from starting. Fixing the fuel pump is not difficult and can be done by inspecting the parts and repairing any damaged pieces of the pump. Often, just cleaning the pump is enough to get it operating again. It should only take you an hour or two to repair the fuel pump and have it running again.
Things You'll Need
Locate the fuel pump on the lawn mower. (It sits beside the fuel tank and has a rubber gas line from the tank to the pump and another fuel line from the pump into the carburetor.) If it is an electrical fuel pump, check the power supply to the fuel pump to verify that it is getting power from your power source.
Disconnect the fuel line to the carburetor and turn the power supply on to verify whether or not fuel is being pumped out of the fuel pump. If not, the problem is in the fuel pump. Detach the fuel pump from the mower with a pair of pliers and a screwdriver.
Inspect the fuel pump by removing the screws with a screwdriver and examining the parts for any signs of wear or damage. Check for any sand or debris in the pump and clean it out.
Replace any gaskets, seals or diaphragms in the fuel pump that are damaged and put the pump back together. Reattach the fuel pump to the mower by connecting the hoses and securing the pump to the mower.
Verify that the fuel pump is working by testing the pump with the carburetor hose detached to see if the pump is pumping out any fuel. Once you have verified that the pump is working, reattach the hose leading to the carburetor.
To prevent any injury, keep your hands and feet away from the lawn mower blade when it is running. Never turn the mower on its side while running.