Does anyone have alot of experiance at reading spark plug reading under a microscope. I am looking at the things that under a naked eye, you could never see.

See http://www.strappe.com/plugs.html

Near the end is a paragraph that reads

Never try to jet too close to a best-power mixture until after you've taken care of spark advance. As previously noted, the air/fuel ratio that yields maximum power is only a shade richer than the one that is most detonation-prone; fortunately, the plug will tell you when there has been even slight detonation inside your engine. The signs to look for are pepper-like black specks on the insulator nose, and tiny ***** of aluminum concentrated mostly around the center electrode's tip. Severe detonation will blast a lot of aluminum off the piston crown, and give the plug a gray coating-which is a portent of death for the engine. A few engines will show just a trace of detonation when jetted and sparked for maximum power, but that never produces anything more than a few miniscule spots of aluminum gathered on the center electrode's sharp edges. If you see more aluminum and an extensive peppering evident on your plug, you're in trouble.

I wonder what "more than a few" and "extensive peppering" means? Two of my plugs had a couple of silver ***** mayby .0005" dia The problem is that I just went one step hotter on the plugs to improve the idle. The motor has no audible detonation.

Andy

 

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