Dang Carburetors!

New owner here with a '77. After reading a number of posts and talking to other owners it seems these carbs are quite finnicky. I rebuilt my set using the Randakk's kit. I reused the needles and seats. The needles looked great. Reused the floats as well. Bike only has 6900 miles on it. I set the float height to 21 mm using the recommended procedure and hooked an IV bottle up to the rack six feet high. No leaks. I installed them on the bike and the plenum gets flooded and the bike stalls. The thing runs OK if I shut the petcock off and on. It is hard to tell but it "appears" the flooding is coming from #4 so I think I will try to shut the fuel off to just that carb to see if I can isolate the problem. Other than rigging up a separate electric fuel pump regulated to 2 psi for bench testing is there anything else I can try? All the other resurrection work is done on the bike and I would like to get this thing on the road.

I just did the same thing with my 81... rebuilt the carbs and had no leaks. When I put the carbs on the bike, I had fuel pissing every where. When I pulled the carbs off again, the #3 float wasn't adjusted right. I reset it, and reinstalled and now I no longer have fuel everywhere.

If you get the auxillary tank high enough, you'll get more pressure. I had to replace brand new aftermarket float valves with oem honda because I couldn't make them seal. Are yours oem or somebody else?

I tested carbs before putting back on the bike by having a lawn mower gas tank above carbs and then swing the carbs around real hard (while off the bike of course) twisting them and turning them 45 degrees in every direction. I do this try to simulate hard riding which when the carbs would surely leak. If I found gas in any of the throats, I would open that carb again and find out why. Almost always a bad float adjustment or a needle and seat not sealing. I clean both by using emery cloth and dragging the needle across while turning in my fingers. The needle often gets a hard surface coating that is uneven and emery will cut through it (think of lapping valves). Always worked for me!

I had similar issues until I got the float heights coordinated. I still start the 81 with the fuel shut off, and shut off the fuel before killing the motor, just to be on the safe side. The 1100 carbs do not have overflow pipes in the bowls like the 1000 carbs.