Rotor Arm for the Lucas distributor in the ignition system of the 2.0L and 2.25L 4-cylinder petrol engines (up to engine suffix C).

Driven by the distributor shaft, the rotor arm routes the high-tension spark from the coil via the centre contact of the distributor cap to each spark plug lead in turn as it rotates. A cracked or eroded rotor arm causes misfire, weak spark and hard starting.