Cylinder Kit 06-09 YZF450, Works Cylinder 21003-K01, 480cc 2007 - 2015 Yamaha WR450F

The Cylinder Works +3mm Big Bore Complete Cylinder Kit (Part Number: 21003-K01) is an upgrade for Yamaha YZ450F (2006–2009) and WR450F (2007–2015) models. Increasing engine displacement to 478cc, this kit enhances power and performance with a direct bolt-on installation. The Nickel Silicon Carbide plated cylinder ensures durability, and the kit includes all necessary components for a complete top-end rebuild.

Features:

• (+3mm Big Bore Kit) increases engine displacement to 478cc.
• Direct bolt-on design, requiring no replating or additional machining.
• Nickel Silicon Carbide plated cylinder for long-lasting performance.
• Precisely honed to exact specifications for easy piston installation.
• Complete kit includes all gaskets and components for a seamless rebuild.

Included Items:

• Cylinder
• Piston
• Wrist pin
• (2) Cir-clips
• Top ring
• (2) Oil rings
• Spacer ring
• Cylinder head gasket
• Cylinder gasket
• Exhaust gasket
• Case gasket

Vehicle Compatibility:

• Yamaha YZ450F: 2006–2009, including the 2006 YZ450FSP 50th Anniversary Edition
• Yamaha WR450F: 2007–2015

Cross-Reference Part Numbers:

• 422-21003K
• 0931-0174
• 733826
• 2792
• HR21003K01
• 77003-25
• 2S2-11311-00-00
• 2S2-11311-10-00
• K8562D300-1ZA
• WT400485100021