Pump Stroke Adjustment
More or less pump stroke is adjusted by attaching the pump rod to one of the holes in the throttle pump lever. They are numbered from 1-4 starting at the bottom. Find your number in the list provided on the instruction sheet included with your carburetor kit.
If you can’t find the number, use position #3.
The check ball in the main discharge is used to block the fuel when the engine is not accelerating, otherwise fuel will be siphoned off during idle. If you see fuel dripping from the Venturi, then this may be the problem. Insert into the middle hole, ball, weight, then bolt. Some 2150 carburetor may have a spring instead of the check weight.
Diaphragms
There are several different accelerator pump diaphragms for the Motorcraft 2150. Be careful to look at the size of the stem in particular.