Starter clutch gear assembly used on a variety of 50cc scooter models with 50cc QMB139 engines, including models from Baja Motorsports (Sun City SC50), Roketa, Taotao & many others This gear is sometimes referred to as a “Bendix”. Description Starter clutch gear assembly used on a variety of 50cc scooter models with 50cc QMB139 engines, including models from Baja Motorsports (Sun City SC50), Roketa, Taotao & many others. This gear is sometimes referred to as a “Bendix”. WARNING California Residents : Proposition 65 Warning Specifications Center Shaft Diameter: 8 mm (5/16″) Starter Gear Diameter: 40 mm (1-9/16″) Total Starter Clutch Length: 70 mm (2-3/4″)