This big bore kit contains the highly sought-after Takegawa 138cc Super Head+R, featuring a ceramic-plated cylinder, 59mm bore diameter, and a 13.0:1 compression ratio. The set also includes a S-20D camshaft, 30mm intake valve and 24.5mm exhaust valve. The kit comes with a Super Head+R head, cylinder, and camshaft, providing unparalleled power and reliability. The Super Head+R head incorporates Takegawa’s renowned technology and OHC’s top-of-the-line large diameter valves, resulting in high output and stable performance in the high RPM range. The use of narrower valve stem shafts and waist processing reduces weight while the roller rocker arm with integrated roller bearings minimizes friction loss. The oil line and oil jet passage in the camshaft enhance durability and lubrication. The cylinder is made of ceramic-plated material for exceptional airtightness, durability, and heat radiation. The piston is








