Replacement starter motor bendix throwout gear suitable for all 139 QMB/QMA engines and Peugeot 50cc Scooters (not suitable for 100cc Peugeots).
The starter bendix creates the link between the starter and the crankshaft and is a common problem for starting issues. Crunching and knocking when starting often point towards a problem with the bendix. Leaving it could cause major damage to the engine cases.