The Cylinder Works High-Compression Standard-Bore Cylinder Kit, manufacturer part number 20001-K01HC and vendor part number 422-20001KHC, is a complete top-end upgrade for select Yamaha YFZ450 models. Designed with a standard-bore cylinder and a 13.0:1 compression ratio, this kit supports strong performance while maintaining a stock-style appearance. It is engineered for riders and technicians seeking a matched, reliable replacement solution without unnecessary machine work.
The kit includes the cylinder, Vertex piston kit, and required gaskets for installation. The nickel-silicon-carbide-plated cylinder is designed for extended service life, consistent performance, and improved durability. Cylinder Works matches the cylinder and Vertex piston to promote longevity, reduce engine noise, and provide dependable fitment. The top-end gasket kit is included but does not contain valve stem seals. Replacement pistons, gaskets, and ring sets are available separately when service is required.
This high-compression standard-bore kit fits 2004–2009 and 2012–2013 Yamaha YFZ450 models. It is intended as a direct replacement-style cylinder kit, and no machine work is needed for standard installation where applicable. Always verify engine configuration, compression requirements, and installation specifications before servicing.
Features:
- Complete high-compression standard-bore cylinder kit
- 13.0:1 compression ratio for enhanced engine performance
- Includes cylinder, Vertex piston kit, and gaskets
- Nickel-silicon-carbide-plated cylinder for extended durability
- Matched cylinder and piston help promote longevity, performance, and reduced engine noise
- Stock-style cylinder appearance
- No machine work needed for applicable standard installations
- Top-end gasket kit does not include valve stem seals
- Replacement pistons, gaskets, and ring sets are available
- Fits 2004–2009 and 2012–2013 Yamaha YFZ450 models
Fitment:
2004 Yamaha YFZ450
2005 Yamaha YFZ450
2006 Yamaha YFZ450
2007 Yamaha YFZ450
2008 Yamaha YFZ450
2009 Yamaha YFZ450
2012 Yamaha YFZ450
2013 Yamaha YFZ450