The Cylinder Works 20003-K01 Cylinder Kit is a complete standard-bore, high-compression top-end solution for select Yamaha YZ450F and WR450F motorcycles. Designed with a 95 mm bore and a 12.5:1 compression ratio, this kit helps restore engine performance while providing a reliable replacement for worn or damaged original equipment components. The kit includes the cylinder, matched piston kit, and required gaskets for a streamlined installation.
Matched with a Vertex piston, the Cylinder Works kit is engineered to support long service life, consistent performance, and reduced engine noise. The cylinder maintains a stock-like appearance while featuring a nickel silicon carbide plated bore for improved durability and wear resistance. No machine work is needed for installation when used with the specified standard-bore application, helping simplify top-end service.
Fitment includes 2006-2009 Yamaha YZ450F models and select 2007-2009 and 2011-2013 Yamaha WR450F models. The top-end gasket kit does not include valve stem seals. Replacement pistons, gaskets, and ring sets are available separately for future maintenance. Verify model year and engine compatibility before ordering. This product is manufactured by Cylinder Works and supplied under vendor part number 20003-K01.
Features:
- Complete standard-bore high-compression kit
- 95 mm bore with a 12.5:1 compression ratio
- Includes cylinder, matched Vertex piston kit, and gaskets
- Nickel silicon carbide plated cylinder bore for extended service life
- Stock-like cylinder appearance
- No machine work required for specified applications
- Engineered for longevity, performance, and reduced engine noise
- Replacement pistons, gaskets, and ring sets available
- Fits 2006-2009 Yamaha YZ450F models
- Fits 2007-2009 and 2011-2013 Yamaha WR450F models
- Top-end gasket kit does not include valve stem seals
Fitment:
2006 Yamaha YZ450F
2007 Yamaha WR450F
2007 Yamaha YZ450F
2008 Yamaha WR450F
2008 Yamaha YZ450F
2009 Yamaha WR450F
2009 Yamaha YZ450F
2010 Yamaha WR450F
2011 Yamaha WR450F
2012 Yamaha WR450F
2013 Yamaha WR450F
2014 Yamaha WR450F
2015 Yamaha WR450F