hey guys new here. i have done my research but couldnt find a whole lot. here it goes. i have a 1994 cbr 600. the bike was running great for a while but i noticed recently when going around 45 my bike sounded like it was spitting out the exhaust... like missing.

i pulled the clutch in to free rev it to see that it hesitated and slowly revved for about 1500 rpm and then it kicked in. If i am in gear and let off the throttle then hit it, it hesitates then goes.

I noticed a power difference as well. The only thing i can think of is spark plugs maybe? I have a D&D exhaust on it and it is cracked right where the pipe meets the can. i dont know if that could be a problem... please help

 

First thing you might try is to seal that leak between the exhaust pipe and silencer joint. I have just replaced my exhaust pipes for stainless ones as mine were rotting through and had holes in the collector box. Ok at high revs, but rough and noisy at low/tickover revs. Welcome to the club!

 

Yeah..seal the leak first...you must do this sooner or later... If problem still exist...then check it bike is starving of air or gas? Can fuel pump play a roll? But only at about 45mph is odd??

 

It's also possible that the bike was never re-jetted for the D&D can.

My 98F3 had a stumble right in that band of 45-5000. When I bought it, it
had a D&D carbon can and an after-market header (Stacked 4x4, not 2x4,
and no cross-over's). I'm a stealth not a screamer, so I ripped it all off and
went back to all-stock. It eliminated the hesitation in the lower mid-range.

I'm thinking it was never re-jetted for the after-market add-ons.
You might have a similar issue.

Another consideration, if it was super-hot when it did this (and is not a constant
issue yet), check the connections on your regulator/rectifier. If they look all
burnt, you could be experience a current failure (hence, low/weak spark).
They have a lousy heat solution and frequently fail.

Hope this gives you a couple of leads, Ern

 

i got the same problem,but mine sudenlly stops not even rididng it,is a cbr 900rr 1998,it seem like spiiting while i push the trothle,after it dies automatically,i dont know what the problem can be,thanks