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TBParts - 1390 PISTON 60mm KLX - YX - ZS - Z125 High Compression Piston kit for V2 Head

Vital Information
Part No TBW1390
Stock Level 2 Left

This is a brand new 60mm (143cc) high compression piston kit we developed for our V2 Race Head due to market changes and requests. It will now be included in all of our 143cc kits that include the V2 Race Head (stock head bore kits will still use the previous piston, TBW0377).

Prior to the Z125, most KLX110 customers were either using the 143cc V2 Race Head kits combined with a stroker crank (which bumps up compression); or on higher compression bigger bore kits (our 165cc kits and up); or they were just using the basic 143cc bore kit with stock head that has decent compression (due to a smaller combustion chamber). Because of those past scenarios, a high compression piston for the 143cc V2 Race Heads was not in high demand. With the arrival of the Z125 (and most of those customers not interested in boring their cases to go to a bigger bore) and with more KLX110 customers interested in remaining at 143cc for new pitbike race class rules, a higher compression piston became in demand so we developed one.

Kit Includes:

  • Piston
  • Wrist Pin
  • Ring Set
  • Cir-clips


  • 11:3 compression ratio – 143cc bore kit combined with the V2 Race Head
  • 12:2 compression ratio – 143cc bore kit combined with the V2 Race Head and our Stroker Crank
In both combinations above, high octane pump gas should be used (Race gas is not required).

Note: This piston kit will also work on the Chinese YX and ZS engines with a 60mm bore combined with our V2 Race Head.

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