170cc / 63mm Big Bore Kit - All KLX140

TB Parts 170cc / 63mm Big Bore Kit Fitment: Kawasaki KLX140 (2008-2020) Kawasaki KLX140G (2017-2020) Kawasaki KLX140L (2008-2020) Kawasaki KLX140R (2021-Present*) Kawasaki KLX140RF (2021-Present*) Kawasaki KLX140RL (2021-Present*) *Fitment Note: 2025+ KLX140s – MAY require case boring to fit. Our cylinder skirt is 65.95mm and SOME 2025+ cases are only 65.4mm wide. This kit includes a lightweight high compression piston that is 5mm over stock making close to 50% more power turning your KLX140 into a race ready machine or a backyard sleeper! We stock replacements for everything in this kit and jets for the OEM carb are linked below.Kit features: Huge power gains at the best price! Aluminum cylinder with steel sleeve (63mm) High compression 63mm piston with rings, pin, & clips (Safe on 91+ Octane Pump Fuel) Top end gasket kit *Fitment Note: 2025+ KLX140s – require case boring to fit. Our cylinder skirt is 65.95mm 2025+ cases are only 65.4mm wide.This kit does NOT require boring of t