Athena Big Bore Cylinder Kit (70cc Bolt On) - 47.66mm Bore 070200 Kits include aluminum cylinder with nickel-carbide coating designed with larger water jackets Includes Forged piston, rings, clips and pin Athena top-end gasket set includes required seals and hardware Easy-to-follow step-by-step installation instructions Most are bolt-on; no machining required except where noted