Starter clutch, also known as 'overrunning starter bypass', 'overrunning clutch plate' and 'one way starter bearing'. This overrunning clutch plate (also known as a starter clutch and starter bypass) assembly applies to (but is not restricted to) 50cc to 250cc GY6 engines and is most commonly used for 50cc to 250cc automatic ATVs, dirt bikes, and buggies/go-karts. The purpose of this component is to prevent damage to the starter when the machine is in operation.