How to Repair a John Deere Lawn Mower

Ensure there is still fuel in your John Deere lawn mower's gas tank. Refill the tank with gas if necessary or add a splash of new gas to the tank if there is older, leftover gas from a previous season. Turn on the mower and allow all the old gas to burn up before using the John Deere.

Fill the John Deere's gas tank entirely with new gas.

Pop the hood of your John Deere lawn mower and check the spark plug if you are still experiencing problems. The spark plug is located near the front of the John Deere's engine assembly and should be connected to the thin, black plug wire. Reinsert this plug wire if it has come loose from the spark plug.

Disconnect the plug wire from the spark plug and consider replacing the spark plug entirely if the John Deere lawn mower's engine still won't start. Insert a new spark plug and reconnect the plug wire to it.

Follow the plug wire back to the rear of the John Deere lawn mower's engine assembly. It will rest just beside the magnetic coil, which in turn sits directly in front of the flywheel. The small gap between the two devices is the air gap. Measure this gap to check if it is between 0.010 and 0.015 of an inch in width. This measurement is important, so be precise.

Move the magnetic coil in relation to the flywheel if the air gap is not between 0.010 and 0.015 of an inch in width. Loosen the magnetic coil for movement by using a wrench, and then slightly adjust the coil. Remeasure the air gap and ensure it meets the width requirement.