Many prefer the closed foam core float as it is supposed to be impervious to alcohol. The hole in the gasket opposite the inlet fuel hole is the pickup for the idle fuel adjustment. The transfer hole across the top is plugged by a small lead shot. If the shot is driven in too far, it will restrict the fuel. If the hole in the bowl gasket is too small, it will restrict the fuel. If the shot is missing, the idle circuit cannot draw up the fuel. They will not idle well if the bug screen between the air silencer and the carburetor is left out. . . 🙂
