The Cylinder Works +3 mm big bore complete cylinder kit (21003-K01) is a direct bolt-on cylinder and piston package designed to increase engine displacement to 478 cc during a full top-end rebuild. It is supplied as a complete kit with the required gaskets and internal components for cylinder replacement and installation.

Features

• Big bore cylinder and piston kit designed to increase engine displacement


• Direct bolt-on replacement design requiring no replating or additional machining


• Plated cylinder designed for durability and wear resistance


• Cylinder supplied honed to specification to support straightforward piston installation


• Complete kit supplied with piston, rings, pin, cir-clips and full gasket set for top-end rebuild work

Specifications

• Manufacturer: The Cylinder Works


• Part number: 21003-K01


• Bore increase: +3 mm


• Engine displacement: 478 cc


• Cylinder plating: Nickel Silicon Carbide

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

Cross-Reference OEM Part Numbers

• 2S2-11311-00-00


• 2S2-11311-10-00


• 422-21003K


• 0931-0174


• 733826


• 2792


• HR21003K01


• 77003-25


• K8562D300-1ZA


• WT400485100021

Vehicle Fitments

• Yamaha YZ450F (2006)


• Yamaha YZ450FSP 50th Anniversary Edition (2006)


• Yamaha YZ450F (2007)


• Yamaha YZ450F (2008)


• Yamaha YZ450F (2009)


• Yamaha WR450F (2007)


• Yamaha WR450F (2008)


• Yamaha WR450F (2009)


• Yamaha WR450F (2010)


• Yamaha WR450F (2011)


• Yamaha WR450F (2012)


• Yamaha WR450F (2013)


• Yamaha WR450F (2014)


• Yamaha WR450F (2015)