Flying Horse 2-Stroke Motorized Bicycle Engine 10 Tooth Front Drive Sprocket &ndash; Gas Bike 10T Engine Sprocket Replacement The 10 Tooth Drive Sprocket is what the motor chain on your 2-stroke 48cc or 66/80cc motorized bike engine rides on To install, use a drive sprocket removal tool to uninstall the sprocket. Once uninstalled, use a flat key and press the sprocket back in to the case