FUNCTION
The function of the accelerator pump is to mementarily provide the additional quantity of fuel needed during acceleration, until the flow delivered from the main metering system increases. This is required whenever thr throttle is suddenly open.
The pump is a piston type pump, operated through the throttle linkage. It is used in stage 1 only. Located inside the float chamber, it is constantly surrounded by gasoline.
When the pump lever is actuated, the pump piston forces fuel through channels and out through the calibrated injection pipe into the carburetor throat.
TROUBLESHOOTING
Examine your plump plunger for damage and sticking. A faulty accelerator pump will cause:
- Hesitation on acceleration
- Stalling
- Fuel consumption
Test the pump lever, there should have slight tension, if not, pump is binding in the bore.
ADJUSTMENT
To check the accelerator pump for proper function the top cover and pre-atomizer in the primary stage must be removed.
- Start of injection immediately on opening the throttle, a powerful jet of fule should emerge
- Injection amount for one full stroke should be 0.7-1.0 cc. Inspect accelerator pump checkballs, inlet and outlet
- Adjust the injection amount by bending the internal lever
- Direction of injection. Pre-1972 and 1972
