Cylinder Works 20010-K01 77.00 mm Standard Bore 13.5:1 Cylinder Kit for Yamaha YZ250F, YZ250FX and WR250F

Upgrade the top end of your Yamaha with the Cylinder Works 20010-K01 77.00 mm standard bore high-compression cylinder kit. Designed for select Yamaha 250F models, this complete kit includes the cylinder, matched piston kit, and required gaskets for a dependable replacement or performance-focused rebuild. The 13.5:1 compression ratio supports strong engine response while maintaining the fit and appearance of a stock-style cylinder.

The cylinder is nickel silicon carbide plated for extended service life, improved durability, and consistent performance. Cylinder Works matches the cylinder with a Vertex piston to promote longevity, reduce engine noise, and provide reliable operation under demanding riding conditions. No machine work is needed for installation when used with the appropriate compatible components. The top-end gasket kit is included but does not contain valve stem seals.

This Cylinder Works kit fits the 2014-2015 Yamaha YZ250F, 2015-2016 Yamaha YZ250FX, and 2015-2017 Yamaha WR250F. It is intended as a replacement cylinder kit for standard-bore applications and provides a practical solution for restoring compression and top-end performance. Replacement pistons, gaskets, and ring sets are available separately for future maintenance. Verify the motorcycle model, year, compression requirements, and existing engine components before installation.

Features:

• Complete standard-bore high-compression cylinder kit
• 77.00 mm standard bore with a 13.5:1 compression ratio
• Includes cylinder, matched Vertex piston kit, and gaskets
• Nickel silicon carbide-plated cylinder for extended service life
• Cylinder styling closely matches the original equipment appearance
• Matched piston helps promote longevity, performance, and reduced engine noise
• No machine work required for compatible applications
• Top-end gasket kit does not include valve stem seals
• Replacement pistons, gaskets, and ring sets are available
• Fits 2014-2015 Yamaha YZ250F, 2015-2016 Yamaha YZ250FX, and 2015-2017 Yamaha WR250F
• Brand: Cylinder Works
• Manufacturer part number: 20010-K01
• Vendor part number: 422-20010K