Originally Posted by Hammond Egger
I wouldn't pull a spark plug out of a hot engine unless I had a spare head and gasket.
Eh, it wouldn't bother me. Yes, I know a steel plug can pull threads out of an aluminum head. Happens in cars, too, but it's after the plugs have been in over very many hot/cold cycles (like 120K miles worth), and even when the engine is cold. If it's gonna happen on a new motor, after the engine has only been run up to temp a few times, I'd rather find out that the head had crappy threads *now,* than after I pay for it and get it home.
The spark plug condition tells you some very important things about the engine. For me, if I'm interested in buying a machine someone else built, I want to see the plug before
I buy it.