Includes springs & rings Kick start shaft & gear for 50cc GY6 139QMB engines This kick start shaft is used on a wide variety of scooters and ATV brands and models that have a Chinese built 50cc GY6 139QMB engine 30 Day Warranty Description Kick start shaft gear for 50cc GY6 139QMB engines. This kick start shaft is used on a wide variety of scooters and ATV brands and models that have a Chinese built 50cc GY6 139QMB engine. Please check the Specifications below to see if this is the correct kick starter shaft for your 50cc GY6 139QMB engine. Specifications Shaft Diameter: 13 mmShaft Length: 47 mm