CYLINDER WORKS B/B CYLINDER KIT YAM YZ450F 06-09, WR450F 07-15, YFZ450/R/X 09-23

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

Majority of our listings are for a direct replacement for your original part.

Our parts are made of quality and are designed to meet or exceed the original OEM Standards.

Our products are often a cost effective alternative to genuine OEM Parts.

Please note: the models of bike we state in our listings are for general guidance only. Please make sure this item will fit your bike before purchasing. Also, we cannot guarantee fitment to any non-UK models.