Carburetor and CDI not Included. 100CC One Piece Cylinders for More Power. Featured Options allow you to upgrade to a Performance Engine buying only the parts you need. 100CC Cylinder with High Hole Piston , Standard 100cc Engine Only, Standard Piston with Intake , Standard High Hole Piston Please note orientation of Standard Piston with Arrow towards Intake. This is factory recommended for best performance. All Engines feature larger diameter 8MM Mounting Studs and Wide Front Mount.