Fuel pump

The pump usually sits inside the tank as a module with the fuel filter, pressure regulator and fuel level sender. It runs for a few seconds when the ignition is switched on to pressurise the system; the short whirr you hear is normal.

Symptoms of a problem

• No pump sound at ignition-on and the engine will not start
• Loss of power or cutting out at high revs or uphill
• An incorrect fuel gauge reading (level sender)

Carburettor motorcycles and scooters usually use a vacuum-operated fuel tap or vacuum pump instead.