Connecting tube is designed to connect the stock Grom airbox to the Koso 34mm throttle body

Intake manifold port is larger than stock and is size matched to use with the Koso throttle bodyInclude all gaskets needed and instructions

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...

34mm Throttle body for increased performance compared to stock 30.5mm throttle bodyIntake manifold port is larger than stock and is size matched to use with the Koso throttle bodyIncludes all gaskets needed and instructions

The Koso 240┬░ camshaft increases power and torque compared to the stock camshaftCan be used with a stock engine, or for optimal gains, use with the Koso 170cc Big Bore KitNot legal for use in California on pollution controlled vehicles, race use only in...

Includes a ceramic coated cylinder, 61mm forged piston, rings, pin, pin clips, gasket kit, and banjo boltsCompression ratio of 11.5 to 1 allows the use of premium pump gas to keep the reliability of the stock motor

Direct replacement for OEM carburetor floatIncludes float pin

Unleash all the power your Honda GROM can handle with the Koso 170cc Big Bore kit.Ceramic coated aluminum cylinder61mm bore, 11.5:1 compression ratio forged piston/ring kit (premium fuel required)Top end gasket kit and banjo boltsNot legal for use in...

Direct replacement for OEM carburetor floatIncludes float pin

Highly recommended for use with all engine upgradesIncreases oil flow by 40%Helps prevent engine failure and lowers oil temperature