what are the effects of spark plug overheating?
Prolonged overheating may induce abnormal combustion (pre-ignition) resulting in melting of the spark plug electrodes. When there is overheating, the insulator surface of the igniter becomes pure white and the burning gases deposit spots. Electrode melting is a more advanced type of overheating and when spark plug temperatures reach 800DegreesC or more (abnormal excessive heat), the tip of the plug may glow red hot and become a source of ignition prior to sparking, causing abnormal combustion (pre-ignition) that can damage the engine.
