Polini 66cc Big Bore Cylinder Kit for 50cc 4-Stroke Yamaha ScootersCOMPATIBILITY: Genuine – Venture 50 4TMBK – Booster 50 4T, Nitro 50 4T, Ovetto 50 4TYamaha – Aerox 50 4T, C3 Giggle 50 4T, Neos 50 4T, Vino 50 4T, Zuma 50F 4T66ccm aluminum cylinder kit from Polini for Scooter with water-cooled Minarelli 4-stroke engines. The cylinder has a 44mm bore.Not legal for use in California on pollution controlled vehicles. Check local laws before installing.**