HI,
I swapped the metal bracket as well. It is something other than the floats, float needles or float bracket. I did notice that the idle needle valve was set at 1/2 turn before I tore the carbs down last spring. the other one (LH) was set at 1 1/4 turns. I set them both at 1 1/2 when I put them back on the engine. I turned the R/H one down to 1/2 but the result was rough running and fuel still comming from the inlet side tube.
Also No electric pump. Chokes are full off. I have them disconnected (choke cable removed)and springs to hold them off.