Hey new to this forum, i just bought a '00 cbr600f4 from the original owner engine is totaly stock and has only 3000 miles. My question is the engine has a hicup, it will do it when it idles all the way up to about 6000rpm, after 6 it just roars. But if the throtle is at 3000rpm and i get on it will hicup. The bike only has 3000miles, the owner said its done it ever since he could remember, he said the dealer told him it just needed to be broken in. Could the carbs be gummed up? Any kind of insight would be helpfull thanks Dan

 

I would pull the spark plugs first and examine them. If they have nice color and are alike, I would replace them and look at the carbs. The piston/ diaphram, that has the jet needle, gets varnish on the plastic slides. The only thing pulling up the slides is differential air pressure. If they are sticky, or the air bleeds are clogged, you will get a hiccup.