Yamaha YFZ 500cc Complete Big Bore Kit (100mm Bore)

This is a complete kit including everything needed to bolt on a 500cc big bore kit for YFZ450 (carb models) from 2004-2013.

  • Complete bolt on kit includes a 100mm cylinder, CP 100mm Piston kit, and Cometic gaskets.

  • Custom designed CP piston is a light weight design, with 14:1 compression on stock stroke crank, and built in clearances for big valves, big cams, and stroker cranks

  • Cometic gasket kit includes head and base gaskets. (always check all clearances during assembly to ensure proper specs due to factory variances)
  • Proprietary cylinder machining increase gasket sealing
    to eliminate head gasket issues

  • Utilizes custom steel sleeve for maximum strength (steel is much stronger than aluminum cylinder with coatings. This is the reason all major auto manufactures have aluminum blocks with steel sleeves!!!!)
  • Designed with additional piston skirt support improving piston and cylinder wear

  • Built in clearance for large stroker cranks

  • Bolts on with no case modification

  • Better ring seal and less blow by equals more power
    Excellent cooling characteristics for the most demanding racing situations

  • Last longer and is more reliable (no coatings to flake off)
  • Great option to fix damaged stock cylinders, and if sleeve becomes damaged a new one can be installed quickly

  • Retains 100% stock OEM look for a stealthy engine build