Another quite likely explanation is that the bike's had a CCT failure, been rebuilt (maybe with timing 180 out- you'll have to pull it apart to find out) and then the repairer has rebuilt it with new valves and head gasket but hasn't had the correct shims available, and just stuck the old ones back in.TUG wrote: (tight walves on front cylinder from lack of maintainace i would assume)
I've stripped a fair few of these engines, and they don't usually go out of tolerance, valve clearance-wise.
Obviously they are designed to be working most efficiently with the clearances in the middle of the tolerance range, but CCT's introducing pistons to valves apart, the clearances don't seem to tighten more than .01-.03, IMHO.
Depends on how the engine's treated. I guess.