Awhile back stealer had my scoot in for install of gear drive cams (TW26G) & tried for 4 days to make good power. It left there 53HP/68TQ. I had it dyno-tuned shortly thereafter at a different shop & only got 70.1HP/85TQ. Since then my fuel mileage has gone from low 40's to low 30's & performance is slowly (but progressively) deteriorating even after warm up. Never any missing, backfiring, coughing etc. Bike is noticeably groggy when cold. 50K on engine, I've checked plugs & they don't look fouled. I've manually adjusted PC III a little w/out lasting improvement. Done a wet sump test & only got a few ozs out of c-case...this stumped the stealer, so I certainly don't expect any miracle cures here w/only my inept description to go on, but anybody got any ideas? I'm not burning any oil, but could the rings be shot? Restricted fuel vent? HELP!

VicW.