Official Lawn-Boy gas lawn mower parts

Common replacement parts for Lawn Boy gas walk-behind lawn mowers

• Sparkplug. The sparkplug ignites the fuel mixture inside the engine cylinder to drive the crankshaft.
• Flywheel key. The flywheel key joins the flywheel to the crankshaft and the flywheel key shears off to protect the engine if the mower blade hits an immovable object such as a rock or tree stump.
• Cutting blade. The cutting blade spins below the mower deck to cut the grass.
• Air filter. The air filter traps dust and contaminants from air entering the carburetor.

How to fix your Lawn Boy gas walk-behind lawn mower when its engine runs rough

If your lawn mower cuts out, smokes, idles poorly, vibrates or runs erratically, it could need a good tune-up to replace the spark plug, oil and air filter. Or the problem could be with the lawn mower's fuel system. Rebuild or replace the carburetor if the engine isn't getting a good supply of fuel.

If the engine misfires, backfires, sputters or jerks the starter rope out of your hand when you try to start it, the flywheel key could be broken. A broken flywheel key disrupts the ignition timing because the magnets aren't passing the ignition coil in synchronization with piston movement. Replace the flywheel key if it's damaged or broken.