Spark plugs are one of the most misunderstood components of an engine.
Numerous questions have surfaced over the years, leaving many people confused. This guide was designed to assist the technician, hobbyist, or race mechanic in understanding, using, and troubleshooting spark plugs. Like a patient's thermometer, the spark plug displays symptoms and conditions of the engine's performance. To remove heat from the combustion chamber Spark plugs transmit electrical energy that turns fuel into working energy. A sufficient amount of voltage must be supplied by the ignition system to cause it to spark across the spark plug's gap.