r/motorcyclerepair

Ive bought a cbr400rrn that hasnt run in over 20 years. Im gradually cleaning and rebuilding the carbs.

The bike has an unbranded aftermarket can on it. It appears a little sooty inside the outlet. When i open the airbox, it had a K&N air filter in there.

The carbs are running main jets that are stamped '.110' that i take to mean is a 110 jet. The slides have Dynojet needles that have the e-clip on the second groove from the top.

The fuel mixture screws are only 1/2 a turn out from fully seated.

From what i have read none of this is right for a std nc29 or a dynojet setup.

I havnt got all the seals etc to try and make it run yet, but id like to get it close upon assembly.

Does anyone habe any base settings?

Hi there, ive recently started to have an issue with my 2001 cr125, for context this issue began after i put a piston and rings into it whether thats a part of my problem i dont know but regardless its important to note. it is well broken in at this point.

My problem is that bogs under load at low revs, in neutral its "okay" but if i grabbed 100% throttle quickly from idle it'll bog and not even attempt to fire or catch up with itself,(important to note that it can be saved by dropping throttle to match revs again). Once it hits the powerband and even a little before it i have plenty of power, more than before the top end rebuild and its just a pity that its so sickly on the bottom end because of how much of a weapon it is when it gets going.

air/fuel adjustments haven't worked, ive checked the carb and carb boot for air leaks, obviously cleaned the carb out.

any help appreciated thanks.