John Deere uses a Kawasaki engine on the premium line of lawn tractors. It is known for being a rugged engine with a long life span. This, however, does not mean it is indestructible; the fuel pump on the Kawasaki is a mechanical pump with a diaphragm. If the diaphragm becomes punctured, the pump must be replaced. A person familiar with the parts involved in the process may complete the task in approximately 15 minutes.
Park the lawn mower on a hard, level surface, remove the key from the ignition and set the parking brake. Raise the hood. Locate the fuel pump that sits directly behind the carburetor and follow the fuel line from the carburetor back to the fuel pump. Note that this is the outlet line. There are two fuel lines going into the fuel pump.
Place the drain pan under the fuel pump. Pinch the hose clamps---using needle-nose pliers---on the fuel lines that are placed over the inlet and outlet barb on the fuel pump and slide the clamps back two inches. Remove the two bolts that hold the fuel pump against the engine with the 10 mm wrench.
Remove the fuel pump, gaskets, insulator and push rod. Inspect the push rod for bending or cracking, and replace it if either is found. Slide the push rod back into position. Place the gasket onto the engine block. Attach the insulator. Place the fuel pump over the insulator and reinstall the bolts. Push the outlet and inlet fuel lines back onto the new fuel pump and slide the hose clamps back into position with the needle-nose pliers.