Melted plastic parts- am I hosed?

[mhardig]

So: I've taken all the crankcase covers off, buffed them, and put them back on, new gaskets, new O-rings. No oil leaks. Fires up without even trying. Once it warms, (<1 minute) I can open the choke and rev it, it seems just fine.

1: While taking the covers off, I noticed that the stator wires were melted- the insulation gone. I also noticed the gearshift position sensor was melted. I was able to replace both pieces from the "donor" engine. This also told me why the crankcase covers were yellowed, it was some kind of varnish that had simply yellowed by being under extreme heat. I have previously replaced other components that were clearly damaged by heat (starter wire, signal generator) What would cause the engine to get this hot? THere is oil pressure and oil is circulating. I don't THINK that the wires were melted because of an electrical fault, because all the electricals seem to be fine. No wires anywhere else on the engine are melted.

2: if the engine has been this hot, is it hosed? It springs to life when you crank it, it doesn't even seem to get a full revolution before it's running. It has good compression. I haven't done anything under load yet, of course, but it seems to rev up to speed easily, and idles nicely. I'd hate to have my first bike die on me before I have a chance to ride it.

Thanks in advance. Sorry for the stupid questions.

[mark]

The only way I know for an engine to get that hot is idling or reving forever in traffic on a hot day, or some other situation where there's no air flow over the motor. If it runs fine, you're probably O.K. I've overheated motors before badly and the electics never melted though. At one time or another you may have had an electrical problem.

By the way, what kind of bike?

[mhardig]

Sorry I left that out

81 GS450T

I ran it up today and discovered it also has an intermittent ground.

I can easily believe the "idled forever with no cooling" thing, here in Chicago traffic is the rule and not the exception. So it's possible the engine didn't sustain any physical damage?

I would think wiring trouble too, except no wiring outside the engine was affected- only wiring INSIDE the engine, or inside the crankcase, I should say.

It doesn't seem to be blowing any oil, so it must have not gotten hot enough to do harm to the valve stem seals, which would be the only other pieces of plastic I'd be concerned about.

[SqDancerLynn1]

The covers always yellow with age /heat its normal for a 25 year old bike