Looking at buying a 96 cbr 600 f3, guy says it bogs down around 6k rpm. Says he cleaned and reinstalled the carbs. Is this likely to be a balancing issue? Or needs actually rebuilt with new parts? Or some other issue? I have been burned by carburetors before lol just trying to see if it's worth taking on the project or maybe too far outside my wheelhouse.

 

When it comes to carbs, you cannot rely on what the seller is saying. Most people do not have the experience or patience to learn how to properly clean and adjust a multi carb set up.

To correctly do this isn’t especially difficult but it does take a good amount of time and exacting patience. If the owner did not fully separate each carb from the others and every component each carb, then they didn’t properly clean them, no matter what they say.

If they did, good money says they didn’t do it correctly. Also if they did, a balance is mandatory.

I’m not overly critical, just honest and watching out for you.

FWIW, a solid carb overhaul begins with checking the valve clearances. If those aren’t right, nothing you do to the carbs will fix an issue. This is especially true with engines of higher mileage.

 

So going into it I should assume completely rebuilding and balancing carbs as well as valve clearance adjustments? The bike has 29k miles and he wants 2k. Worth it for a project or no in your opinion?

 

29k isn’t a lot of miles if the bike has been reasonably maintained.
you should assume all that you said will need to be done.
If you are fairly mechanically inclined, patient, and willing to learn, the good news is that it is a job that can be done on your own. A few specialized tools will be needed. There are many videos to watch on properly doing the work plus the forum is full of posts of people doing exactly what you are considering.
If you don’t want to do the work, there are services available to get it done for you.

I really can’t speak to the price though it doesn’t seem terrible if the bike is in decent shape.
a lot depends on your region. Where I live that would be a deal worth considering. In other areas that would be too much.

 

That seems like good value for bike with low miles. Wonder if you can check with DMV to verify actual mileage on record?

Yeah, count on at least measuring valve-clearances, then adjusting to large end of range. Then do compression-test afterwards.

For carbs, proper restoration job goes beyond “cleaning”. Spray “carb cleaners” no longer work after mid-‘90s due to removal of chlorinated compounds. Carb must be completely disassembled down to every last nut, bolt & individual component. Everything scrubbed witb PEA-based fuel-system cleaner. Including secret hidden passages in carb body. Poke out all bleed holes with matching gauge soft copper wires. Everything ultrasonic soaked and micro soda-blasted. Replace all rubbers: float valves, pilot-screw O-rings, fuel-rail O-rings, float-bowl seals and even slide-diaphragms if needed. Set float heights and do rough sync. Follow with sync on-bike.

Lots of work requiring decades of experience and lots of specialised equipment. Best to send to pros for restoration work. Expert workmanship, reasonable fees and quick turnaround. Bike will run like brand-new off showroom floor.
https://customcarbservices.com