*It is a kit that uses an STD cylinder head. *The piston needle bearing is not included. It is recommended to purchase the parts number: NEED-50 at the same time. *It is a carburetor setting but it replaces depending on the chamber or other remodel specification. Please note for those who can set it. *Please do not mount in relation to catalyzer exhaust of emission control vehicle. *Please make sure to modify the application with local government in case of using it in public road.