John Deere's 100 Series lawn tractors make it easier to mow a large yard or acreage compared to a push mower. The 100 Series tractors are powered by a small engine that powers the mowing blades and the drive-train of the tractor. If the John Deere mower runs poorly or does not start as expected, the manufacturer has recommended troubleshooting steps to find the problem. There are many models of the John Deere 100 Series lawn tractors, but the troubleshooting steps are the same for most of them.
Things You'll Need
Press the brake pedal firmly and attempt to start the mower. The brake pedal must be fully depressed before the engine will start.
Check the fuel tank to make sure the tank is full. If the fuel tank is below the full mark, you may need to add gasoline.
Move the blade engagement lever all the way forward to disengage the blades. The tractor will not start if the blades are not disengaged.
Check the spark plug wire to make sure it is seated properly. Pull the spark plug wire off the spark plug, using your fingers. Press the spark plug wire firmly onto the spark plug.
Replace the spark plug. Use your fingers and remove the spark plug wire from the spark plug. Use a socket wrench and remove the spark plug. Install the new spark plug with a socket wrench and tighten it securely. Push the spark plug wire onto the spark plug firmly, using your fingers.
Allow the engine to cool completely before working near the engine.