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...

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