Note: The accelerator pump has only two adjustments. Piston-to-shaft pin position is set at factory. Capacity adjustment should be made only if operating arm is replaced.

Pin Position Check

1. Remove upper body of carburetor. Turn upper body assembly upside-down.

2. Disconnect pump from operating arm.

3. Disassemble spring and nylon keeper that retains adjustment pin.

4. Check pin position. Refer to specifications. If pin is not in correct hole, remove pin and place in specified position.

5. Reassemble nylon retainer, spring and spring retainer. Reinstall into upper body.

   

Capacity Adjustment (After Pump Arm Replacement)

NOTE: Throttle plates, shafts and lever must be installed to specification to properly adjust new pump arm.

1. Remove mechanical fuel bowl vent rod and bracket assembly.
2. Remove two expansion plugs (1 brass, 1 aluminum) from air horn over pump arm. This gives access to adjusting screw and pin hole.

NOTE: Penetrate plugs with sharp punch and pry out

1. Remove carburetor upper body.
2. Remove vacuum piston limiter lever and nylon pump arm from pump lever and shaft assembly.
3. Remove pump adjusting screw (5/64” allen wrench) from original nylon pump arm.
4. Install adjusting screw in new pump arm. Position so that one full threat of the point end of screw shows below pump arm.
5. Install nylon pump lever and shaft assembly with “E” clip.
6. Mount upper body to main body.
7. Install pump rod into correct hole in throttle pump lever.