KOSO 4 Valve Cylinder Head

The Koso 4V Head Kit is the ideal engine part to complete the Koso Honda Grom® Big Bore kit. Because of its unique 4 valve design, the air flow and performance are increased. This new designed head is the perfect addition for those who desire more power and torque.

• Not legal for use in California on pollution controlled vehicles, race use only in California - waiver available.
• Requires the use of Iridium spark plug
• The 4 Valve Head Kit features a forged piston, stainless steel 24 mm intake valves and 20 mm exhaust valves. Only fits Koso 170cc big bore kit.