10 Teeth Electric Starter Motor for GY6 50cc Scooter Moped Parts Electric Starter Motor without Wire for 50cc 4-stroke QMB139 engines. Fits most Chinese made GY6 based 50cc scooters. Bolt Hole Spacing: 70mm; Total Diameter of Shaft: 7.25mm, 10 Splines No assembly required and can be installed in minutes. Please check pictures/dimensions before the purchase.