The Solex 44 PA1 marine carburetor uses a diaphragm for the accelerator pump.





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.
No, or weak squirt
Most likely something is plugged up. The 1st suspect would be the brass discharge tube because it has such a small orifice. Remove it and do the test over to eliminate the part.
Make sure the pump spring is between the diaphragm and the carburetor body. The instructions show this wrong.
Blow through the holes as pointed out above to make sure air goes through all of them.
Adjusting the Pump