Grinding and mechanical noises when starting the engine are often a sign that the starter clutch is faulty. The carrier sticks and no longer releases properly. In the worst case scenario, this can be catastrophic for the motor. As many parts of the starter mechanism are inter-connected, they are all subject to a fair bit of wear. Replacing the starter clutch and all related components helps with this. All relevant parts included in the kit. Suitable for all 125/150cc GY6 4-stroke 152/157QMI engines.