My Account Support

Free Shipping.

Expert Service.

Koso 150cc Big Bore Kit

Item: 420064

$411.95

Select Your Vehicle - Fitment Guaranteed

Need Help?

Free Shipping

Fitment Guaranteed

Description Fitment Reviews Q&A

Koso 150cc Big Bore Kit

  • Compression ratio allows the use of premium pump gas and keep the reliability of a stock motor
  • Kit includes aluminum black powder coated cylinder, 54 mm forged piston, rings, pin, pin clips and gasket kit

Kit Includes:

  • Cylinder
  • Piston
  • Rings
  • Pin
  • Pin clips
  • Gasket kit
Specification Details
Bore 54.00mm
Color Black
Compression Ratio 11.38:1
Displacement 150cc
Finish Powder Coated
Material Aluminum

Vehicle Fitment

Fitment is guaranteed or your money back plus free return shipping.
Don’t waste time installing a product that doesn't fit. We worked hard ensuring that this product is an exact fit on the vehicles listed below.

Honda
  • MSX125 Grom 125 2022-2026
  • Monkey 2022-2026
  • Monkey ABS 2022-2026

Customer Reviews

Be the first to review this product. How many stars would you give this product?

Questions & Answers

do you need a new fuel injector when changing from 125cc to 150cc

By mike

No, a performance injector isn't required to install this kit on any machine you select from our fit guide. Yes, Koso recommends one, but specifically states that it is not required.

By Tom

Have a question? Please ask our experts and customers who own this product.