|If the high voltage pulse of the ignition coil runs away
with the carbon fouling , the spark plug will misfire
, and the engin would have problems while driving .
||When overheated , the insulator nose appears become
white electrode melted . The attached fouling has spot,
If it is further heated , the electrode would burn away
. If the temperature reaches 800oC , the insulator nose
will have pre-ignition , which would harm the engine