TBparts - 55mm 138cc Big Bore Kit for Honda CRF125

This will make your trail bike a lot more fun to ride by adding some much needed power. With the larger bore, this bolt-on upgrade kit will give you more power and higher compression for a very reasonable price. This kit does not require boring of the case – simply bolt on, tune (Not included) and go!! This is an ideal option if you’re looking to add some power or you just need a new cylinder, piston, and rings to rebuild your engine.

Key Features:

• High quality, high compression 55mm piston, with rings, pin, & clips
• 11.0:1 compression ratio compared to stock 9.0:1. Our piston is pump 91+ octane gas friendly.
• Aluminum cylinder with steel sleeve (55mm)
• Head gasket kit with exhaust gasket!
• Largest bore you can go without boring the cases
• More power and fun at an affordable price
• Easy bolt-on kit
• +2.6mm of bore or 13cc

Kit Includes:

• TBW1713 - 55mm Cylinder 
• TBW1714 - 55mm Piston kit 
• TBW1715 - 55mm Gasket set