Is valve seizure a common malady? If so, can I visually determine that was the problem and what can I do to prevent future occurrences? Also, I will post some pics and introduce myself in the other forum. Thanks for any additional guidance.
I have a KZ1000 engine where a valve seized and the valve head was broken off. But I'm pretty sure this was a result of the engine sitting outside, the open valve stem rusting in place, and then someone coming along and kicking it over. So not what you're describing, but it is an example of a seized valve.
It seems like it's worth very closely inspecting the valve guides in your head, and possibly having the guides replaced while you have it apart. It's also worth measuring the valve to piston clearance as well.
The only other thing I can think of is that some of the J model cranks were prone to twisting. The pieces are press-fit together, and some were too loose. I have no idea if this twist could be enough to shift the cam-to-crank timing enough that a valve touches the piston.
