Im new to this forum so i just want to say thanks in advance for any help at all, i just bought a '99 cbr 900 with 15k on it. bike ran great for about 3 days then while riding it, the bike cut out and jus died. (just lost rpms and slowly died like it had lost a charge or somthing?) towed it home and played with it after the motor had cooled down.. wouldnt turn over, wanted to start but didnt, so i replaced the spark plugs and saw that all four of them were black as hell, 2 looked like they were gunked with too much fuel.after that started the bike and it fired right up but was only running on 3 cylinders. (the 1st or 4th cyl. was dead, if your standing behind the bike facing the tailight, the one on the far right) its not banging or tapping or anything, just dead. put my hand on that particular header pipe and it was ice cold while the others were hot, im thinking its an electrical problem since its not pinging or poping. its just not firing. if any body here has had any thing like this happen to them and is there any wya to fix this myself, anywhere i should start?? im out ofideas, thankyou

 

Normally a bike still can be fired up even one cylinder is down. Did you hear any sort of jamming sound when the bike is about to go down? How is the engine oil and its level? Any breakdown history? 15k miles for a 99 is pretty low.

It might be premature to conclude the cylinder is dead. Check out those plug cables in good condition or not, can be the culprit as well.

Hope the ECU is not burned; if its an electrical problem.

 

1st thing: check to see if the dead cyl has spark. I'll bet it does, since you said it ran great prior to dying out. If it does, I'll be it needs a carb clean. Do all of them, not just one. If you can't handle it, take it to someone who can, so you don't end up with more problems. Also, since you said all plugs were black, it seems too rich. check your air filter condish, and find out your jetting specs and change if need-be. hope this helps. jd