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Motorcraft Accelerator Pump

Testing the Accelerator Pump Circuit.

After rebuilding your carburetor, test the accelerator pump before putting it on the car.
2150 Accelerator Pump - Stroke

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.
If you can't find the number, use position #3.
2150 Accelerator Pump - Check Ball

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.

Check weight measurements:
Length: .879
Diameter: .11
Make one from aluminum. Optionally add a 2nd check ball for the weight.
The accelerator pump diaphragm is used to deliver an extra squirt of fuel when you press down on the accelerator.

Any leaks around the diaphragm cover edge is probably caused by a warped cover. Put it in a vise, clamp down gently, add heat to it, clamp down a little more, allow to cool. If that doesn't work try filing the corners where the screws go in.

The Motorcraft 2100 normally used one diaphragm pump (except for the 1957) . The Motorcraft 2150 uses several accelerator pump diaphragms. Most of our pumps can be found by entering the carburetor number in the search box. Unfortunately many 2150 carburetors are missing the carburetor tag number. In these cases you will need to match up the old pump with our new pumps. Each pump includes the measurements, which should get you to the correct pump.


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2150 Accelerator Pump Diaphragm

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