The spark plug uses the electricity generated by the ignition module to create a spark that ignites the air fuel mixture in the combustion chamber. The intense heat in the combustion chamber, along with the high voltage used for ignition, will cause the spark plug to wear. The electrodes will wear away with use, causing a weak or inconsistent spark. If the fuel mixture isn't just right, the spark plug can become coated with carbon or tar -- again causing weak or inconsistent spark. If the fuel mixture is too lean, or if the wrong spark plug is used, the ceramic insulator can crack. The spark plug should be inspected often and replaced at least once per year (or more often if needed).
Let's get started.
REMOVING THE SPARK PLUG 1. Remove the spark plug.
a. Remove the spark plug boot from the spark plug.
b. Use a spark plug wrench or socket to loosen the spark plug.
c. Remove the spark plug from the cylinder.
INSTALLING THE NEW SPARK PLUG
2. Install the spark plug.
a. Use a spark plug gapping tool to set the spark plug gap to .025 inches.
b. Thread the new spark plug into the cylinder.
c. Secure the spark plug with a spark plug wrench or socket.
d. Reinstall the spark plug boot.