Refresh the top end of your two-stroke motocross bike with the Cylinder Works 20009-K02 Standard Bore Cylinder Kit. Designed for 1999–2008 Yamaha YZ250 models, this complete replacement kit includes the cylinder, piston kit, and gaskets needed for a dependable engine rebuild. The standard-bore configuration is intended as a direct replacement for the original cylinder and is designed to restore consistent performance without requiring additional machine work.
The Cylinder Works cylinder is finished with a nickel silicon carbide plating for extended service life, improved wear resistance, and reliable heat management. Its stock-style appearance allows it to integrate cleanly with the factory engine configuration. The kit is matched with a Vertex piston to support durability, strong performance, and reduced engine noise during operation. The included top-end gasket kit does not include valve stem seals.
Use the Cylinder Works 20009-K02 as a replacement standard-bore top-end solution for compatible Yamaha YZ250 applications. Replacement piston, gasket, and ring sets are also available separately for future maintenance. Always verify the motorcycle model year and engine configuration before installation to ensure proper fitment.
Fitment: 1999–2008 Yamaha YZ250
Manufacturer Part Number: 20009-K02
Vendor Part Number: 20009-K02
Features:
- Complete standard-bore cylinder kit
- Includes cylinder, piston kit, and gaskets
- Matched with a Vertex piston for durability, performance, and reduced engine noise
- Nickel silicon carbide plated cylinder for extended service life
- Stock-style cylinder appearance
- Designed as a replacement cylinder for standard-bore applications
- No additional machine work required for installation
- Top-end gasket kit does not include valve stem seals
- Replacement pistons, gaskets, and ring sets are available
- Fits 1999–2008 Yamaha YZ250 models
Fitment:
1999 Yamaha YZ250
2000 Yamaha YZ250
2001 Yamaha YZ250
2002 Yamaha YZ250
2003 Yamaha YZ250
2004 Yamaha YZ250
2005 Yamaha YZ250
2006 Yamaha YZ250
2007 Yamaha YZ250
2008 Yamaha YZ250
2009 Yamaha YZ250
2010 Yamaha YZ250
2011 Yamaha YZ250
2012 Yamaha YZ250
2013 Yamaha YZ250
2014 Yamaha YZ250
2015 Yamaha YZ250
2016 Yamaha YZ250
2017 Yamaha YZ250
2018 Yamaha YZ250
2019 Yamaha YZ250
2020 Yamaha YZ250
2021 Yamaha YZ250
2022 Yamaha YZ250
2023 Yamaha YZ250
2024 Yamaha YZ250
2025 Yamaha YZ250