170cc Koso Big Bore Cylinder Kit w/4V Cylinder Head for 125cc Honda Grom, Monkey SPECIFICATIONS: Cylinder Displacement: 169.2cc Cylinder Material: Aluminum/Ceramic Coated Cylinder Overall Height: 90.5mm Piston Diameter: 61mm Piston Type: Forged Compression Ratio: 11.5 to 1 This complete 170cc Big Bore Kit with 4V Cylinder Head Kit is the perfect add on for all horsepower enthusiasts looking for performance! It includes a 170cc ceramic coated cylinder, forged piston, performance camshaft, bearing, rocker arms, 4 valve cylinder head, intake manifold, gaskets, and more. All parts are made from High quality components for reliability and durability that allow you to put your mind at ease and ride with confidence! ***WARNING: THIS IS AN AFTERMARKET PART BUILT FOR RACING PURPOSES ONLY. Scooterdynasty.com and KOSO ARE NOT RESPONSIBLE FOR ANY DAMAGES CAUSED TO THE PARTS, VEHICLE, OR TO YOURSELF AND OTHERS. ENGINE PARTS ARE NOT UNDER WARRANTY NOR IS COLLATERAL DAMAGE OR COST OF LABOR, IN CASES OF MALFUNCTION.** **