KFX400 / LT-Z400 / DR-Z400 90mm Stock Bore Race Kit – Athena (2000-2016)

Rebuild with factory-level performance—no machining required. Bolt-on stock bore kit with Factory Works porting, 12.2:1 piston, and race-proven durability for ATV, supermoto, or dual-sport builds.

The Athena P400510100001 is a complete 90mm stock bore race cylinder kit for 2000–2016 Kawasaki KFX400/KLX400, Suzuki LT-Z400/DR-Z400, and Arctic Cat DVX400. Features nickel-carbide cylinder with Factory Works porting, 12.2:1 forged domed piston, hard-anodized power valves, and full gasket set. Cylinder head not included.

What's Included

• 90mm Nickel-Carbide Cylinder – Factory Works porting
• Forged Domed Piston Kit – 12.2:1 compression, rings, pin, clips
• Hard-Anodized Power Valves – high-flow, non-OEM
• Athena Top-End Gasket Set – head/base gaskets, seals, hardware

Key Features

• 90mm stock bore — direct OEM replacement, no boring required
• Nickel-carbide plating — extreme durability, low friction
• Factory Works porting — max airflow, race-tuned performance
• 12.2:1 forged piston — aggressive mid-top power
• Hard-anodized power valves — faster response, longer life
• Made in Italy — pro-grade precision

Fitment

• 2003–2006 Kawasaki KFX400
• 2003–2006 Kawasaki KLX400 / KLX400R
• 2003–2014 Suzuki LT-Z400 QuadSport Z / LE / SE
• 2000–2016 Suzuki DR-Z400 (all variants)
• 2004–2008 Arctic Cat DVX400

Install Notes

• Reuses OEM cylinder head (not included)
• Bolt-on install — no machining required
• Advanced install — top-end rebuild experience recommended
• Jetting/fuel tuning may be required for optimal performance