hi i have a 92 cbr 600. nightmare lately i bought that bike last month. ran flawlessly for the first two weeks. then it started idling like crap and stalling when getting anywhere passed cool temperature. i tried everything including Sea-foam carb cleaner, that i added to my fuel tank. that did not help. i pulled every single plug, checked the air filter, check every fuel line, took the fuel line of and tested the petcock, checked every vaccum hose that i could find (there are a lot of them) and still nothing. i also checked the fuel pump (which might be my problem what do you guys think?) i gently unscrewed the back of the petcock and the fuel pump seperated a little bit and i screwed it right back together. (i didnt start the bike since i put the Sea-foam in). so now i start the bike and it still idles like ****, and now i cant go passed half throttle. (white in neutral of course) i can twist the throttle all i want and its smooth. but as soon as i get to half throttle the bike practically shuts off!! after 6 hours i tested the coils and wires wth a voltmeter and found out that my #4 wire had barely any resistance. so i replaced that and now it starts and idles great. but i still cant go passed half throttle!! its so friggin weird! if i slowly build on the throttle (while in neutral) the rmps are smooth and steady, as soon as i get to 5800 rpm (about half throttle) the bike engine just completely dies and will just shut off if i hold it there.

its like a do or die. it doesnt slowly run like crap the higher rpms i get. its great. perfect. and at half throttle just immediately shuts off. what do you guys think?? its kililng me

 

anyone? its killing me. tried EVERYTHING

 

Sounds like a fuel issue - float levels ?
Pinched fuel line (don't laugh, it happens)
Hard to tell from here......

 

thanks for the response. i havent checked the floats but i wouldnt think float level because it idles fine. and im not getting any fuel spilling out of the carbs. could that still affect it? and the fuel lines good ive checked it a millliioonnn times. im getting plenty of fuel to the carbs. ive taken the fuel tank on and off literally 20 if not more times. the vaccum lines to the fuel pump and the fuel line are all good

edit: oh and ive checked the drain bolts on all 4 carbs and they were all full with fuel and poured out. so im getting plenty of gas from the tank

 

Your bike has a fuel pump? My '91 doesn't. Mine's gravity fed. Sounds like the dreaded dirty carbs!! You'll need to take them off and apart and go through them. I had to do it to mine to make it run. There's a Hell of a carb cleaning tutorial in the tech. section. I highly recommend it. I'm going to sync. mine this weekend so mine should clean up 'tween idle and 2K. Good luck!

 

You've mentioned the fuel pump a couple of times, but the F2 (in stock form anyway) does not have a fuel pump or fuel filter, other than the screen at the bottom of the tank, where the petcock connects...I know it seems like a dumb question, but, are you sure this as an F2 and not an F3?

 

Well its a 1992 600. Almost positive its an f2.... and i am positive that this diaphram with the rubber disks and the spring in the back of my petcock is a fuel pump.. and there is a vaccum hose that goes to it to pressurize the tank. And i dont think this bike has a fuel filter? Cant find it anywhere. But thats not the problem because when the petcocks off fuel flows 100%. And its not gravity because when i take off the tank and turn the petcock to on or reserve no fuel comes out but when i pressurize the tank it fllowss out. And idk how the carbs could get clogged in a matter of 10 minutes. Possible i guess tho. Maybe the SeaFoam carb cleaner moved sone dirt in the carb into a jet or orphus in the carb.

 

It isn't. It's a vacuum actuated valve. When there is vacuum it opens the valve letting fuel into your carbs. When the engine isn't running no fuel can get into the carbs. That way if you have a bad float needle and or seat you won't come out to a puddle of fuel on the ground and a crankcase full of gas either. Nope, there's no fuel pump on your bike.

 

It is INSIDE the tank. Flip the tank upside down and take the petcock off, trust me its in there. I had a rubber grommet get stuck inside the small in tank filter and was causing a blockage and it would bog and sometimes die. Definitely worth looking at. Pull the carbs off and clean them DEEP (float bowls and needles, jets) with carb cleaner and compressed air. Good luck! I've been having fuel delivery issues for the past 3 months or so, I feel your pain

 

+1 on it being a fuel starvation problem. There is either a blockage in the tank, the lines to the carbs, or a blockage in 1 or more of the carbs main jets.