Motorcycle Repair: VIRAGO 750 engine noise, yamaha virago 750, stethascope

Question
Wayne,
     I have an 82' Yamaha Virago 750 which has a terrible noise coming from the top end I beieve,but not positive. The noise is not there when cold as soon as it starts to warm up after about 3-4 minutes it will clatter then progressively get worse into a clunking sound. When this first started I was riding and started losing power but didnt hear any noises. I then shut it off, restarted it and heard the noises. my valve clearances are at .009" what are they suppose to be?  I know this is hard to diagnose like this but any suggestions? Thanks for your help!

Answer
Gary,

try locating the sound with a mechanics
stethascope or a long screwdriver held
to your ear.
Try setting the valve clearance
tighter, about .004"-.006"

It could be valve clatter or cam problems, also check if
oil is getting to the top end,
does it look oily?

You may need to do a compression check
or leak down test to see if the pistons
are scored.

You may need a partial teardown to determine
the cause unfortunately.