Plug electrode MIA

Sometimes I continue to marvel at what an engine will endure and never complain. Found a tempest fine wire with the electrode fully gone. This wasn't even detected in a runup/mag check. I guess it was still firing "fine".

Seems unlikely that a mag could fire a gap that big. You sure you didn't see an EGT rise on that cyl during runup? One plug may not make that large of an RPM drop and be unnoticable. I suppose the crud inside the insulator is carbon and conductive, making it possible.

Larry

?Fine?....... good one Scott - you must have a pretty good mag to jump a gap that big.

My IO-540 developed a miss on runup last weekend, Tempest fine wire in #3 had 1/3 of the insulator missing. I'll post pics when I get around to it.

-Marc