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TB Parts

170cc / 63mm Big Bore Kit - All KLX140

  • Sale
  • $ 179.95


TB Parts 170cc / 63mm Big Bore Kit


Kawasaki KLX140 (2008-2020)
Kawasaki KLX140G (2017-2020)
Kawasaki KLX140L (2008-2020)
Kawasaki KLX140R (2021-Present)
Kawasaki KLX140RF (2021-Present)
Kawasaki KLX140RL (2021-Present)


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

This kit does NOT require boring of the case – simply bolt on and go! There are no installation instructions, but if you can replace your piston, you can install this kit. If you don’t have any experience working on your engine, we highly recommend having a professional technician install this kit or, at a minimum, purchasing the shop manual for your bike available from your local Kawasaki dealer. The parts are installed in the same manner as the OEM parts.

Installation note – KLX140 camshaft bolts are reverse threaded, turn them right/clockwise to loosen/remove. Factory Carb Starting point for jetting is #40 or #42 Pilot and a Main Jet of #100 or #105. A performance exhaust will require a larger main jet #105 – #110

Jets for stock carb – Pilot jets – TBW1458, Main jets – TBW1584

This kit includes:
TBW1544, TBW1545 and TBW1543