-The 40 FP''s as do all the FP series Have bleeder carburators. The number one mistake the fellows make with these is to not adjust the mid range adjustment at all because they do not know its there, where it is or which way to turn the screw.

Thats because its a screw in the front of the carburator that covers up a direct hole (facing forward) that goes directly into the venturi. This type of midrange adjustment is rare these days in modern engines and - it is backwards of all other midrange needle valves, unlike those others you unscrew it to make the mid range mixture leaner.

Talk to your mentors about this. Additionally you may have the fuel tank to spraybar relationship a little off. While there is a wide range to work with its best to start off with the center line of the fuel tank roughly level with the jet or spraybar in the carburator.

John