Determine if the spark plug needs to be replaced by examining the gap for the problems listed below:

The gap is bridged by corrosion.

The gap is too large.

The area around the gap is black and dark.

If the spark plug doesn't need to be replaced, return it to the spark plug bore. If it does need to be replaced, use a new one.

Use a ratchet, extension, and 5/8 socket to tighten the spark plug by turning clockwise. Use your hand to tighten as well.