CYLINDER WORKS Cylinder Kit Ø66.4 mm for YAMAHA YZ 250 and FANTIC XX 250 1999-2024

On YAMAHA YZ 250 and FANTIC XX 250 from 1999 to 2024, the CYLINDER WORKS Ø66.4 mm 20009-K02 cylinder kit fits in place of the original part. A cylinder that is scored, oval or has a damaged coating loses compression and wears pistons out quickly. Rather than having it rebored and recoated, this kit replaces it with a new, ready-to-fit cylinder.

Specifications

• Brand: CYLINDER WORKS
• Manufacturer part number: 20009-K02
• Engine: 4-stroke

When to replace it?

• Cylinder scored or coating flaking after a seizure.
• Ovality or taper out of tolerance when measured with a micrometer.

Measure the cylinder at every piston change. As soon as it falls outside the tolerances in the manual or is scored, it has to be replaced or reconditioned.

Fitting tips

1. Carefully clean the top of the crankcase and cover its opening before removing the old cylinder.
2. Oil the supplied piston and check the ring end gaps before fitting the cylinder.
3. Use new gaskets, either those in the kit or a suitable top end gasket kit, and tighten the cylinder and head in a criss-cross pattern to the manufacturer's torque.
4. Fit a new spark plug and refill the coolant.
5. Break the engine in gently for 3 to 4 hours, as Athena recommends for its cylinder kits.

Why CYLINDER WORKS?

Cylinder Works makes new, not remanufactured, cast-aluminium cylinders to the original design. The bore is electroplated with nickel silicon carbide and diamond-honed to exact size: an alternative to an OEM cylinder or a re-plate, with a forged Vertex piston matched to the cylinder in some kits.

Spare parts and items to plan

• Piston : WISECO · ATHENA
• Piston rings : VERTEX · PROX
• Top-end gasket kit : ATHENA · PROX
• Piston pin clips : WISECO
• Spark plug : NGK 3430 · NGK 3130
• Coolant : LIQUI MOLY 1 L · TWIN AIR

Frequently asked questions

What does the kit contain?
The cylinder and its complete piston. Check the photo and the Athena instructions for the gaskets supplied.

Which spare parts should I plan for?
For the next service: piston, rings, pin, circlips and top end gaskets in the same size as this cylinder.

Compatibility

Check the exact model and year of your bike in the list below before ordering.

Fits:
FANTIC XX 250 2024
FANTIC XX 250 2023
FANTIC XX 250 2022
YAMAHA YZ 250 2024
YAMAHA YZ 250 2023
YAMAHA YZ 250 2022
YAMAHA YZ 250 2021
YAMAHA YZ 250 2020
YAMAHA YZ 250 2019
YAMAHA YZ 250 2018
YAMAHA YZ 250 2017
YAMAHA YZ 250 2016
YAMAHA YZ 250 2015
YAMAHA YZ 250 2014
YAMAHA YZ 250 2013
YAMAHA YZ 250 2012
YAMAHA YZ 250 2011
YAMAHA YZ 250 2010
YAMAHA YZ 250 2009
YAMAHA YZ 250 2008
YAMAHA YZ 250 2007
YAMAHA YZ 250 2006
YAMAHA YZ 250 2005
YAMAHA YZ 250 2004
YAMAHA YZ 250 2003
YAMAHA YZ 250 2002
YAMAHA YZ 250 2001
YAMAHA YZ 250 2000
YAMAHA YZ 250 1999