Accelerator Pump circuit not working properly? Popping out the carb when you hit the throttle? This is the first thing we will check as they clog very easily. Assuming these are clear work back to the Pump Pressure Valve, Pump Suction Valve, and the Accelerator Pump Itself. New Old Stock. No Longer Available from MB. Included in 0000715301RK - Complete Carb Rebuild Kit.