The sprocket is mounted on the outer edge of the flywheel after being heated and secured there upon cooling. It engages with the starter gear to rotate the crankshaft and start the engine.

1) When starting the engine, the starter gear may collide with the flywheel teeth ring, or the teeth may not mesh properly, causing the ring to be damaged.

2) The starter's power connection was too early, causing the starter gear to collide with the flywheel tooth ring.