TBparts - 149cc Big Bore kit with Forged Piston for Grom and Monkey

Key Features:

• High quality, Forged, high compression 55mm piston, with rings, pin, & clips
  
• 11.8:1 compression ratio compared to Stock 10:1. Our 11.8:1 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
  
• Clearance to retain factory piston oil squirter
  
• Easy bolt-on kit
  
• +4 HP! More gains if you have a performance Exhaust and Intake

• Grom - 2022-Present
• Monkey - 2022-Present

Kit Includes:

• TBW1596 - 55mm head gasket kit
  
• TBW1585 - 55mm cylinder
  
• TBW1595 - 55mm piston kit
  

Note: These bore kits are only for the 2022 and newer models (will not work on the 2021 and older models as the engine has been redesigned) A performance intake and exhaust is recommended if you want to get the most power possible! (Not necessary) This product is legal for closed-course competition use only; for racing vehicles (a competition vehicle not used on public highways). Intended for off-road use or race purposes; may not meet regulations of pollution controlled roads or highways. Not legal for vehicles registered and use in California.