PISTON KIT 83-87 YZ250 68.50, WOSSNER 8133D050 YAMAHA MX

This Wossner 68.50mm (+0.50 oversize) forged piston kit is designed for Yamaha YZ250 models from 1983 to 1987. Precision-engineered and manufactured in Germany, this piston features a forged construction for maximum strength and durability. The elliptical design ensures a uniform bearing surface during thermal expansion, reducing localised pressure and distributing thrust loads evenly to prevent piston collapse. It is optimised for effective heat transfer from the combustion chamber to the cylinder walls, making it well-suited for high-performance two-stroke applications.

Features

• Forged piston for enhanced strength and longevity

• Elliptical design ensures uniform surface contact during heat expansion

• Minimises localised stress and evenly distributes thrust loads

• Supports efficient combustion heat transfer to cylinder walls

• Manufactured in Germany

Specifications

• Bore: 68.50mm

• Actual diameter: 68.44mm

• Displacement: 246 cm³

• Stroke: 68.00mm

• Clearance: 0.06mm

• Compression height: 36.00mm

• Compression ratio: 2-stroke

Cross-Reference OEM Part Numbers

• Piston Kit Part No.: 56-W560+050.WO

• Wossner Piston Kit No.: 8133D050

• Lock: CW18

• Pin: WP033

• Ring Set: RDB6850

• Rod: P2048 (for 1983–1989 models)

Vehicle Fitments

• Yamaha YZ250 1983

• Yamaha YZ250 1984

• Yamaha YZ250 1985

• Yamaha YZ250 1986

• Yamaha YZ250 1987