Motorcycle Repair: 2002 r1, missing ring, cylinder valve

Question
My problem started when I would accelerate the bike would stutter and fall on its face! The shop said I had a 100 pound loss in the #1 cylinder. Valve clearance was fine and no missing ring or shavings anywhere. Had a lot of build up on pistons but seems normal for a bike with 12000 miles. Any ideas?

Answer
Hi Ryan,

Sorry to answer this so late.
Are there any scratches or gouges in the cylinder? Sometimes when there is build up on the pistons, a small piece can crack off and scratch the cylinder walls.
Other then that, the rings might be worn or the cylinder is worn out.

-Jeff