ATHENA Racing Forged Piston for KAWASAKI KDX 200 1986-2009

The ATHENA Racing S4F06600002A forged piston (Ø 65.94 mm) is designed for KAWASAKI KDX 200 from 1986 to 2009. A forged piston is made by squeezing a hot aluminium slug in a press, instead of pouring the metal into a mould. The metal is denser and stronger: the piston copes better with high revs and heat, which makes it the choice for racing engines.

Key features

• High-silicon aluminium alloy, forged by reverse extrusion.
• CNC machined to a tolerance of less than 0.01 mm, tested on the bench and on the track.
• Rings made in Japan, with a PVD or chromium nitride coating.
• Supplied with pin, circlips and ring(s).

Specifications

• Brand: ATHENA
• Manufacturer part number: S4F06600002A
• Engine: 2-stroke
• Size: A (check that it matches your cylinder)
• Piston diameter: 65.94 mm
• Weight: 370 g

When to replace it?

• Loss of power, sluggish pick-up, harder starting: compression is dropping.
• Piston slap on a cold engine, getting more and more noticeable.
• On teardown: vertical scoring on the skirt, stuck or worn rings, thick carbon on the crown.

Replace the piston as set out in your bike's service manual, sooner if you race, and straight away as soon as these symptoms appear. As a Cross-Mania guideline, plan for a new piston every 20 to 40 hours of engine running depending on whether you race or ride for fun. Always measure the cylinder at the same time: a new piston in an oval cylinder won't last.

Fitting tips

1. Clean the cylinder and check it: diameter, ovality, taper and condition of the bore coating.
2. Check the end gap of each ring in the cylinder against the figures in the manual or the manufacturer's instructions.
3. Fit the rings with the mark facing up and each gap correctly located on its locating pin.
4. Check the small-end needle bearing and the pin: at the slightest play, tight spot or marked needle, replace the bearing.
5. Fit the piston with its arrow pointing to the exhaust side, oil the pin and the small end, then fit the circlips without distorting them, gap opposite the notch. A circlip that has been taken out is replaced with new piston pin circlips, never refitted.
6. Reassemble with a new top end gasket kit and tighten the cylinder head in a criss-cross pattern to the manufacturer's torque.
7. Refill the coolant and fit a new spark plug.
8. Break the engine in: warm it up gently, vary the revs and avoid sustained full throttle for the first hour.

Why ATHENA?

Athena, an Italian company founded in 1973 near Vicenza, designs gaskets, pistons and cylinder kits for motorcycles. An OEM supplier to KTM, Ducati, Fantic, Piaggio and Triumph and a partner of the MXGP world championship, it develops its parts on the test bench and on the track with racing teams.

Spare parts and items to plan

• Piston rings : WISECO W2677CD · WISECO W2638CD
• Piston pin : ATHENA · WOSSNER
• Top-end gasket kit : ATHENA · CENTAURO
• Small end needle bearing : ATHENA · PROX
• Spark plug : NGK 5722 · NGK 3981
• Coolant : LIQUI MOLY 1 L · TWIN AIR
• 2-stroke oil : LIQUI MOLY 1 L 3065 · LIQUI MOLY 1 L 3063

Frequently asked questions

Does the piston come complete?
Yes: piston, pin, circlips and ring(s). The top end gasket kit has to be ordered separately, because a head or base gasket can never be reused.

Can I replace just the rings later?
Yes, as long as the piston and cylinder are still within tolerance. Replacement rings can be ordered on their own, as can the piston pin and the circlips.

Should I replace the small-end needle bearing?
It isn't included. Check it at every piston change and replace the needle bearing at the slightest play or tight spot.

Compatibility

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

Fits:
KAWASAKI KDX 200 2009
KAWASAKI KDX 200 2008
KAWASAKI KDX 200 2007
KAWASAKI KDX 200 2006
KAWASAKI KDX 200 2005
KAWASAKI KDX 200 2004
KAWASAKI KDX 200 2003
KAWASAKI KDX 200 2002
KAWASAKI KDX 200 2001
KAWASAKI KDX 200 2000
KAWASAKI KDX 200 1999
KAWASAKI KDX 200 1998
KAWASAKI KDX 200 1997
KAWASAKI KDX 200 1996
KAWASAKI KDX 200 1995
KAWASAKI KDX 200 1994
KAWASAKI KDX 200 1993
KAWASAKI KDX 200 1992
KAWASAKI KDX 200 1991
KAWASAKI KDX 200 1990
KAWASAKI KDX 200 1989
KAWASAKI KDX 200 1988
KAWASAKI KDX 200 1987
KAWASAKI KDX 200 1986