13-1. FUEL SYSTEM/CARBURETOR/ FUEL PUMP/ FUEL TANK GRAND DINK 125/150 FUEL PUMP CONSTRUCTION: The fuel pump adopted for this model is a vacuum-type fuel pump which utilizes the positive and negative pulsating pressures produced by the engine crankcase to control the oil pump diaphragms and deliver fuel from the fuel tank to the carburetor through the suction valve and outlet valve. FUEL PUMP CONSTRUCTION Outlet Valve Outlet Diaphragms Suction Valve Pulsating Pressure from Crankcase Inlet 13-4