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

Dispatch Times

Local Stock: Dispatches in < 24 hours

Parts showing as available at our Warehouse in Gorey ship the same business day if ordered before 1pm. 

Supplier Stock: Dispatches in 2-4 Days

Parts showing as available at our Supplier Warehouse are ordered from our supplier and delivered to us before we can dispatch. More info is available on this page under "Stock Availability".

OEM Special Order: Dispatches in 3-10 Days

This website does not have access to live stock levels from our OEM Suppliers. In most cases the parts will be available but in the case of backordered parts we will notify you. We receive parts from Yamaha in 3-4 days, All others including Honda, Suzuki, Kawasaki, Polaris please allow 7-10 days for us to receive the parts. 

Delivery Times

Ireland & Northern Ireland:

1-2 Days using GLS/An Post

Germany, France, Netherlands, Belgium:

3-5 Days using GLS/Fedex

Italy, Spain & Other EU Countries:

4-7 Days using GLS/Fedex