CB750f rebuild Carburetor problems

[Steveo]

I am working on a 1980 CB750f cafe racer project but I am having troubles with the carburetors. No.2 and 3 are continuing to overflow and I can not figure out why. First I cleaned them with CRC carb cleaner, also cleaned out the tank. Next I replaced the float valves, still no joy. The seats look in good condition to me and the floats seem ok. Also they seem to be moving freely enough. I have checked the bowls its not leaking out of the drains.

Anyone have any more ideas?

 

[Steveo]

Well just got called to go back to sea tomorrow. Looks like I won't be working on the bike until August.