How to Troubleshoot a Troy-Bilt Self-Propelled Lawn Mower
- 1). Position the Troy-Bilt mower in a well-lit workspace. Wear work gloves at all times. Remove the rubber boot from the end of the spark plug, grounding it against the cylinder, before making any mower repairs.
- 2). Unscrew the air filter box, mounted to the backside of most Troy-Bilt self-propelled mowers, but always next to the carburetor. Disconnect the throttle control lever from the choke. Unscrew the choke plate from on top of the carburetor.
- 3). Unhook the two plastic fuel tubes from the backside of the carburetor. Tilt the engine slightly backward and watch for fuel. Fuel should exit the tubes, indicating enough fuel is reaching the carburetor. If fuel isn't reaching the carburetor, service the fuel system.
- 4). Unscrew the spark plug and pull it from the cylinder. Fit a test plug straight into the rubber boot. Hook the test plug up to the cylinder, so its electrode tip is about three centimeters away from a grounded metal point on the engine cylinder.
- 5). Stand back from the blades and make sure they won't hit anything should the mower start. Pull the recoil starter several times and look for a blue spark. If there's no spark, or it's a weak yellow, service the ignition system.
- 6). Remove the test plug from the rubber boot and reground it against the engine cylinder. Screw the compression gauge directly into the spark plug hole. Tug rapidly on the starter rope until the compression needle maxes out. Compression should read from 60 to 110 psi for a good reading. If compression is low or drops off rapidly, service the air and compression systems.