If an engine is to work correctly, fuel needs to be delivered continuously and in fixed proportions to the engine. This is the function of a well maintained fuel pulse pump. With the use of pulses, a pre-defined quantity of fuel is delivered to the engine in a steady stream
A pulse fuel pump has four tubes connected to it. One tube connects the fuel tank. Two tubes connect each carburetor and one tube connects the crankcase of the engine. When the engine revolves, the tube connecting the engine delivers fuel with a pulse of pressure at each revolution. The diaphragm pulsates with the pressure. At the top of the pump are two chambers. They are separated by a pair of one way valves. These valves ensure that the fuel that passes through does not come back. Fuel flows from one chamber to the other at one pulse and at the next pulse, fuel moves to the engine. A well maintained pump works at 5,000 pulses per minute.