Wossner Piston Kit Yamaha YZ250F 2001-2004 77mm 12.5:1 Compression 8559DA

The Wossner 8559DA piston kit is engineered to restore or upgrade your YZ250F's top-end with precision-matched components that handle sustained high-RPM operation. Factory OEM pistons wear, lose compression, and compromise throttle response—this German-engineered kit returns your engine to specification or improves upon it with superior materials and heat treatment. Whether you're rebuilding after piston failure or preventive maintenance before race season, Wossner's complete kit eliminates guesswork and ensures reliable performance.

Each kit ships ready to install with all components needed for a professional top-end job: piston, compression rings, wrist pin, and circlips. The 4032 T6 forged aluminum construction resists detonation and thermal stress far better than budget alternatives, while the permanent skirt coating reduces friction and noise during cold starts and extended idling. German engineering combined with FEA optimization means every dimension is tuned for your bike's combustion chamber and rod geometry.

• Fitment: Yamaha YZ250F 2001-2004
• Bore diameter: 77mm
• Compression ratio: 12.5:1
• Material: 4032 T6 forged aluminum
• Piston skirt coating: Permanent friction-reducing
• Heat treatment: T6 specification
• Design method: FEA-optimized
• Kit contents: Piston, rings, pin, clips
• Installation: Bolt-on replacement
• MPN: 8559DA