Re: 96 900rr stumble/miss
yes, dirty/blocked jets can cause knocking/tapping noises, as its been sitting a long time sounds like the jets are blocked, take them apart and give a good clean to idle jets and main jets, use carb cleaner and compressed air. When finished make sure you sync the carbs.
Some of the early blades I had, had a bit of a piston slap, they tend to do it at about 2-3 rpm. loads of them do it.
cct sound is more a tapping sound than a knocking sound, this could also be one of your problems, as these tend to play up more on a cold engine, also if you had an air leak from somewhere on exhaust system,(normally downpipes, or exhaust nuts lose on head) this could also cause a tapping noise, and as metal expands, the noise can go away.
Last edited by stevecbr1000; 04-17-2012 at 5:05 PM.