ROCKER ARMS 64MM VALVES GY6 49CC 50CC 139QMB SCOOTER ATV Scooter Rocker Assembly. Fits many 50cc China Made GY6 Four Stroke Scooters with the QMB139 Engine. Work with heads that have 64mm length valves The shipping cost within the Continental US is included in the cost. Please note, any product that is returned will be refunded minus the original shipping costs.(i.e. The cost to ship the order to you) Please Note: many photos are stock images and although no functionality will change, the part you receive might vary in color or aesthetic appearance.