Cylinder Works 10007-K01 10-13 Honda CRF 250 R 250cc Standard Bore Cylinder Kit 13.2:1 Comp. 76.8mmCylinder Works 10007 K01 10 13 Honda CRF 250 R 250cc Standard Bore Cylinder Kit 13. 2: 1 Comp. 76. 8mm Description Cylinder Works Standard Bore Cylinder Kit Fits Models CRF 250 R (10 13) Specs Uses Vertex #23510 Compression Ratio13. 2: 1 Cylinder Diameter76. 800 mm Cylinder Kit Type: Standard Bore Displacement: 250 cc Engine Type: 4 Cycle Includes: Cylinder, Piston Kit, and Top End Gasket Kit