Accelerator System
Function of accelerator pump is to provide fuel when throttle is suddenly opened, and before main jet system begins to operate. On pressure stroke of pump, fuel is forced out of pump body through bores, and injected into mixing chambers through calibrated injector pipes. As soon as throttle valves are closed suction stroke of pump begins. During suction stroke fuel flows from float chamber, by way of pump valve, into body of pump. Pump suction valve prevents fuel from flowing back into float chambers during pressure stroke of pump. An additional ball valve, in injector pipe, prevents air from entering pump interior during suction stroke. Length of pump stroke governs amount of fuel to be injected. Calibration of injector pipe determines duration of fuel injection cycle.