How to Repair a John Deere L120 Mower

The John Deere L120 mower is a front-engine mounted riding

model. The mower might require simple troubleshooting related to insufficient gas or slightly more elaborate repairs to parts in the engine assembly that may be worn out or slightly misadjusted. Fortunately, you can troubleshoot and repair your John Deere L120 riding lawn mower even if you have never attempted mechanical repairs before. No special tools are required.

Wrench

Instructions

- 1
  Check the gas level of the John Deere L120 mower if it isn't starting. Fill the gas tank if it is out of gas.
- 2
  Remove the front cover over the engine if the mower continues to fail to start.
- 3
  Disconnect the spark plug wire from the spark plug if you suspect the spark plug may be malfunctioning due to age. Replace the spark plug with a new one.
- 4
  Test the mower and see if it starts with the new spark plug. If not, open up the mower's front cover again.
- 5
  Check the rear of the engine assembly for the magnetic coil. This circular part can be found by following the trail of the spark plug wire back to it. Behind this magnetic coil is the flywheel. The flywheel nearly touches the back of the magnetic coil, and this slight aperture created between the two is the mower's air gap.
- 6
  Measure the size of the air gap. The air gap should be between 0.010 and 0.015 of an inch in width. Loosen the magnetic coil with a wrench and apply a slight bit of pressure to both the outside of the flywheel and the outside of the coil. This should adjust the gap. Re-measure the air gap after making the adjustment and ensure it falls between the correct range.
- 7
  Replace the mower's front engine cover and turn on the machine.

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