With bowl cover assembly inverted and float resting on pin in seated needle, the vertical distance from the projection tip on edge of float chamber cover (A) to soldered seam of float should be 5/16″. Do not put any pressure on the needle, or it will be damaged and the carburetor will flood.
High Speed Adjustment
A high speed needle is to be found in the bowl cover behind the pump lever bearing post as shown below. To adjust the carburetor for best economy with the engine warmed up, speed up engine on floor, with the throttle stop screw or hand throttle, to a speed corresponding to approximately 30 miles per hour. With a screwdriver, screw high speed needle in a clockwise direction until the engine begins to lose speed. Turn screw back in anticlockwise direction until the maximum speed is attained.