Q10:Why is the firing end appearance of a spark plug important?

　　A： Because the firing end appearance reflects the suitability of the spark plug as well as the condition of the engine.

　　These are the three basic standards for evaluating a spark plug.

　　Spark plug tip temperature and firing end appearance

　　The border-line between the fouling and optimum operating regions(500¡ãC)is called the spark plug self-cleaning temperature.

　　It is at this temperature that accumulated carbon deposits are burnt off.