PISTON 98-00 YZF/WR400F 92 HC, WOSSNER PISTON KIT 8639DA

Wossner forged piston kit designed for high compression and performance. Engineered for optimal heat transfer to cylinder walls, ensuring efficient combustion. The elliptical design provides a uniform bearing surface under heat expansion, reducing localized pressure and evenly distributing thrust loads to prevent piston collapse. Manufactured in Germany to high-quality standards.

Features

• High-compression forged piston for enhanced performance


• Optimized heat transfer for efficient combustion


• Elliptical design to prevent piston collapse


• Manufactured in Germany

Specifications

• Bore Size: 92.00mm


• Actual Bore Diameter: 91.95mm


• Displacement: 399 cm³


• Stroke: 60.10mm


• Clearance: 0.05mm


• Wossner Compression Ratio: 13.50:1


• OEM Compression Ratio: 12.50:1


• Dome Volume: -4.60 cm³


• Compression Height: 24.10mm


• Theoretical Weight: Not specified

Included Components

• Lock Part Number: CW18


• Pin Part Number: WP053


• Ring Set Part Number: 920XSY

Vehicle Fitments

• Yamaha WR400F (1998-1999)


• Yamaha YZ400F (1998-1999)