Starter clutch assembly. Used on a variety of 50cc scooter models with 50cc QMB139 engines including the Baja Sun City (SC50) and many others. Center Shaft Diameter: 8 mm (5/16") Starter Gear Diameter: 40 mm (1-9/16") Total Starter Clutch Length: 70 mm (2-3/4") ![]() | |