Fuel enters the accelerator pump reservoir through the hole in the bottom of the fuel bowl.
Fuel enters through the pump intake. The pump intake check ball allows fuel to flow in using the weight of the fuel and the suction from the diaphragm. When pressing on the throttle, the check ball prevents the fuel from re-entering the fuel bowl.
When pressing on the throttle, fuel enters the main discharge passage through the hole as illustrated. The check ball at the fuel intake prevents the fuel from re-entering the fuel bowl.
When pressing the throttle, fuel travels to the main discharge hole as shown above. There is a brass tube mounted here (not shown) that directs the fuel into the bore.
Testing Your Accelerator Pump
With the engine off, remove the spark arrestor.Look into the carburetor bore and pump the throttle.You should see 1 strong squirt of fuel going into the bore.
Watch a video to see how to test the accelerator pump circuit while on the bench.
Adjusting the Pump