Here's one for the collective XR gurus.
I'm working on a friend's 1999 Honda XR600R, (for free of course because I'm stupid,) with an issue that's not apparent. The engine will rotate with the kickstart but locks up before it reaches a full rotation. If I turn the engine backward (in gear), it will rotate but locks in the opposite direction. If I remove the cylinder head cover the engine will rotate freely. If I put the cover back on it will lock up as before. I can’t see any marks or signs of damage anywhere up top. I pressed the cam sprocket holder off of the camshaft, inspected the decompressor assembly and everything looks fine. The rocker assembly moves freely and shows no sign of damage. I also pulled the clutch side off to inspect for anything that looked out of place and it looks perfect.
The bike ran fine, he shut it off and when he went to kick it over it locked up.
Has anyone had this issue before?