Throttle

On a motorcycle, throttle means both the right-hand twist grip and the valve it operates. Turning the grip opens a butterfly valve in the throttle body (fuel injection) or a slide in the carburettor, letting more air into the engine. The injection system or carburettor adds the matching amount of fuel, so power rises.

Traditionally the grip pulls one or two cables. Many modern bikes use ride-by-wire, where a sensor reads the grip position and the engine control unit opens the throttle with a motor, enabling riding modes, traction control and cruise control.

Check that the throttle snaps back to closed on its own with the bars turned fully left and right. A sticking throttle is dangerous; clean, lubricate or adjust the cables and set the correct free play.