Starter The starter is the device that is responsible for initiating the rotational motion of the engine. This device replace the old style hand cranks found on many very early cars. The starter works on a switched circuit with the ignition key. When the key is turned the starter receives power from the battery. This power then engages a clutch that pushes the starter gear to the gear on the flywheel of the engine. The motor then turns, thus turning the engine. When the engine reaches speed, or the power is removed, the gear retracts to prevent damage to the teeth.