Koso 150cc Big Bore Kit – Honda Grom & Monkey (2022+)

Made from the best components available on the market, Koso’s 150cc Big Bore kit is the perfect addition to upgrade your performance! The kit includes a black powder coated cylinder, 54 mm forged piston, rings, pin and gasket kit. Its compression ratio of 11.38 to 1 will allow you to still use premium pump gas and keep the reliability of a stock motor.

***Please Note: You may need to modify your engine case to accommodate the larger cylinder***

*Please note: Compatible with 2022 and newer Honda Grom and Monkey

• Cylinder Displacement: 150cc
• Cylinder Material: Aluminum/Black Powder Coated
• Piston Diameter: 54mm
• Piston Type: Forged
• Compression Ratio: 11.38 to 1