basically here's what happened, i'm open to suggestions:

1996 cbr 900rr

revved bike up, hit rev limiter for a couple seconds, after that it started running like ****. it appears to be missing on the #3 cylinder. there is spark, and overall the motor itself isnt making any out of the ordinary noises. But the exhaust sounds like a V-twin now. We pulled the airbox off, and while the bike was running, we got a couple backfires through the #3 carb. sprayed some berryman carb cleaner in all the carbs while running, each one nearly stalled the bike, as it is supposed to, except the #3, which when we sprayed it, the bike seemed to idle correctly. My dad and a buddy of mine who are both mechanics both say it looks like its something with the valves. Pulled the valves apart today and they look fine, nothing obvious.

also we did a leak-down test on the #1 and #3 cylinders, only a 6% loss on #1, but a 20% loss on #3, which leads to believe it is a valve problem.

Gotta get this thing goin ASAP, we're goin to vegas in a week to ride. Any help is very appreciated.

 

Sounds like you might have bent a valve. Causing it not to seal completly.

 

have u already overruled rings? sounds valve related definatly tho, can u flip the head and put some water in the chamber and blow some comepressed air up the port? if so you might be able to see where the air is leaking up from and maybe just lap the valve a little bit

 

sounds to me like an air leak somewhere.. i use that test to diagnose cars... sprak carb cleaner around and once you hear the engine speed up, you found your leak. u sure a vacuum line didnt pop off or something simple???