Cylinder Works replacement Cylinders! - Cylinder looks just like stock - Nickel silicon carbide plated for longer life - No machine work needed * - Replacement cylinder for standard bore only * Honda CRF250R and CRF250X may require slight case modification. Kit comes with instructions. Fits: Yamaha WR250F 2015-2019 YZ250F 2014-2016 YZ250FX 2015-2016