fuel pump

A fuel pump is a component used in many liquid-fuelled engines (such as petrol/gasoline or diesel engines) to transfer the fuel from the fuel tank to the device where it is mixed with the intake air (such as the carburetor or fuel injector).
Carbureted engines often use low-pressure mechanical pumps that are mounted on the engine. Fuel injected engines use either electric fuel pumps mounted inside the fuel tank (for lower pressure manifold injection systems) or high-pressure mechanical pumps mounted on the engine (for high-pressure direct injection systems).
Some engines do not use any fuel pump at all. A low-pressure fuel supply used by a carbureted engine can be achieved through a gravity feed system, i.e. by simply mounting the tank higher than the carburetor. This method is commonly used in carbureted motorcycles, where the tank is usually directly above the engine.

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