Hi, I have a 1996 cbr600f3 that’s been having some “bogging” issues. So this might be a lot I apologize for the long paragraph. The issue Iv been heaving is nothing Iv experienced before with carbureted engines. so basically in first gear it revs through all the rpm’s, in 2d gear (if it’s warmed up) it will rev through all the rpm’s as well. now 3 gear is where it “stutters” it’ll hit a specific rpm around 5k and sit there and stutter, what I mean by this is it doesn’t really fall on its face, it’s getting gas still but the bike doesn’t want to go past that 5k rpm mark almost as if it doesn’t have enough power to go past that rpm range but it still has enough to stay there. Any of the other gears it just does the same stutter thing until you get to 5th or 6th in which it then falls on its face like the “out of gas” feeling. I would like to note that any gear you shift into you can cruise as long as you’re not trying to brap it up and really get into it. So essentially I can’t go past around 5-6k rpm and I can’t go past around 50-60mph on it. Now Iv replaced the fuel pump bc it was ticking bad and I also have to rev the bike to 3krpms to let the choke out otherwise it dies which can be an indication of a bad fuel lump I figured it just wasn’t getting the amount of gas it need. That didn’t fix the issue. along with that Iv replaced the fuel pump relay and taken the carbs apart and cleaned it. The carb was spotless and my next goal is to throw everything back together and maybe see if the carbs need to be re synced. If that’s not the issue I’ll be at my wits end. Lastly I forgot to mention that the person that had the bike before me, apparently he had a coolant hose hooked up to the vent port on the bottom of the gas tank🤦‍♂️ so I’m sure there some other things that would be ****ed as well. I’d appreciate any info thanks!!

 

Classic symptoms of clogged dirty carbs. Needs complete disassembly down to every last nut, bolt & individual component.

Everything scrubbed with PEA-based fuel-system cleaner, especially hidden secret passages in carb-body. There's some 90-degree bends that accumulate clogs. It's parts you can't see internally that's most problematic.

Poke out all bleed-holes with matching gauge soft copper wire.

Ultrasonic soak everything, micro soda-blast all pieces before re-installing.

Replace all rubbers: float-valves, fuel-rail O-rings, pilot-screw O-rings, float-bowl seals, even slide-diaphragms if needed.

Bench sync, then on bike with manometers.

This is lots of work and requires decades of experience on hundreds of carbs, needs specialized equipment. Not worth acquiring all this just for one set of carbs. Send to pros for restoration work. Expert workmanship, reasonable fees, quick turnaround. Bike will run like brand-new off showroom floor!

https://customcarbservices.com