Generally a change to a colder plug is done to aviod detonation from increased compression, advancing timing(Combustion chamber hotter) or if evidence of overheating of the plug is apparent(usually caused by continuios high speed operation),just as a hotter plug is recommended in worn engines to avoid oil/carbon fouling. When you remove a spark plug, what does the end look like? What colour is it? Does the ceremic look bleached/blistered?. I have always had exceptional results from the NGK V groove range of plugs, the only brand (apart from Golden Lodge,N.L.A.) that has never let me down with dud plugs or premature failure.
Fri, 24 May 2002 03:08
