Not the "usual"? Why, besides having long-distance bike trips, or surprise pregnancies, near-death experiences, career-change stress, religious quandries, unhappy love-life woes, or getting named after cartoon characters... This seems no more odd like the usual slice of life stuff that floats through here, Howard :-)


> > Anybody have any more ideas? I also have an aluminum engine with an overtightened spark plug. This usually results in stripped threads and a ruined cylinder head. Any ideas on that one. Fortunately the spark plug is on a spare engine and not the one on the scooter I just bought.
> > Howard

> Another thing you can try after the Mystery Oil soak is using a propane torch to heat the plug. Be careful not to get the insulator too hot. It'll shatter. Focus the tip of the flame right where the steel of the plug and the aluminum of the head meet. Heat it up til you think the plug is about operating temperature. Give it a little crank while it's hot. Give it another when it cools off. The different rates of expansion of the two metals will help break it loose.

The heat differential-expansion method works well. I have seen it done in the case of certain cars, where you *really* don't want to snap off the plug inside its seat (because then it costs mega-$$$ to take apart the engine to get at the broken plug). What you do is get the propane torch to heat up and expand the plug and the head where they meet, just like Dan says. Then you blast the hot plug itself with a shot of canned xenon (or freon) gas, which will cause the plug to contract and loosen up considerably. Works every time like magic.


> If these fail and the threads get stripped, it's Heli-Coil time.

What's "Heli-Coil"? The only heli-coil I know is a modification of a vigreux-like column within a glass manifold system, but I doubt you were thinking of that :-)

Wolfspirit