1999-2024 YZ250 2-stroke TOP END Big Bore Kit -Cylinder, Piston, Head, Gaskets

  

Hassle Free, direct bolt on equipment, no machining or boring required. Take off the old parts and install a 293cc New cylinder, power valve, piston and gaskets.

Made with larger water jackets for greater cooling capacity. Ported power valves for more power and torque over the stock YZ250 This kit is a direct bolt on, comes complete with A new Cylinder!

Keep all your original parts! Complete New Aluminum Cylinder with a Nickel Carbide Coating designed with wider water jackets.

Ported power valves for more power and torque over the stock YZ250. Kit was made to be a improvement over the Athena YZ293 big bore.

Improved power valve porting and uses factory style flat metal gaskets for increased reliability over the rubber o-ring Athena gaskets. Cometic gaskets and Athena pistons are also made to work with this kit.

Some items may have a slightly different appearance than what is shown in the picture. Please review the entire description to verify proper fitment.