Motorcycle Repair: gas leaking from carb air vent tube, honda cb750, vent tube

Question
1992 Honda CB750 Nighthawk

I just stripped down my carbs, and gave it a good cleaning.  Reassembled it and did a test drive.  I noticed that there is fuel coming from the number 3/4 air vent tube that is connected to the carbs.  Is the fuel leaking because the float valve isn't sealing?  If it is, should I replace the float valve?  Or is it leaking because of something else?

Thanks,
Duc

Answer
You are right ...you have one or more needles that are not sealing to the seat and allowing excess fuel in to the carbs and out the overflow into the vent....reclean the carbs and pay special attention to the needles and seats...also make sure your floats are not fuel saturated...anything that looks suspect...replace

Deron