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TBParts - Roller Rocker Race Head V2 146cc Big Bore Kit China 120 & 125cc engines

Vital Information
Part No TBW9127
Stock Level 7 Left

All of our 125cc engine big bore kits are for 78mm tall cylinder engines only
Most China 125cc pitbike engines are 69mm tall cylinder type engines
Your engine MUST have a 78mm tall cylinder to use this kit.
Please see TECH LINK for more details

TB Roller Rocker Race Head V2 146cc Big Bore Kit
China 120 & 125cc engines
Highest Performance Race head on the market with full parts support in stock.

Key Features:

  • Roller rocker arms exactly like the V2 head for the KLX110
  • 28.5mm intake Valve
  • 23.5mm Exhaust Valve
  • 5mm valve stem
  • 23mm exhaust port
  • Matching high compression piston head kits include all hardware
  • 57mm piston with rings, pin, & clips
  • 57mm all aluminum cylinder with steel liner
  • High performance race camshaft (for the Race Head only)
  • Head gasket kit


  • Sta-bil fuel stabilizer - W-57-1109
  • 26mm Intake - TBW0433
See the Performance Info section for additional information on our performance parts.

OD of cylinder skirt is 59mm


  • China 120cc & 125cc engines with a 14mm wrist pin

Kit Includes:

  • TBW0751 - V2 Race head
  • TBW0821 - V2 Head bolt kit
  • TBW0752 - Cam
  • TBW0754 - V2 Head cover set
  • TBW0414 - Cam sprocket
  • TBW0824 - Piston
  • TBW0862 - Top end gasket set
  • TBW0601 - Cylinder

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Since 2004, every purchase from TBolt USA includes access to technical support from our staff of experts and our online Pit Bike Technical Info Database!

We have all necessary support parts on hand.

Most orders ship same, or next business day, unless otherwise noted above.


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