PISTON KIT 86-88 YZ125 56.75, WOSSNER 8118D075 YAMAHA MX

This Wossner 56.75mm (+0.75 oversize) forged piston kit is designed for Yamaha YZ125 models from 1986 to 1988. Featuring a forged build and elliptical design, the piston is engineered for thermal expansion control, even thrust load distribution, and reliable performance in two-stroke engines. Manufactured in Germany, it ensures efficient heat transfer from the combustion chamber to the cylinder walls under demanding conditions.

Features

• Forged piston construction for enhanced strength and durability

• Elliptical design provides consistent bearing surface under thermal expansion

• Even distribution of thrust loads minimises localised stress and prevents piston collapse

• Optimised for efficient heat transfer from combustion chamber to cylinder walls

• Manufactured in Germany

Specifications

• Bore: 56.75mm

• Actual diameter: 56.69mm

• Displacement: 123 cm³

• Stroke: 50.00mm

• Clearance: 0.06mm

• Compression height: 30.00mm

• Compression ratio: 2-stroke

Cross-Reference OEM Part Numbers

• Piston Kit Part No.: 56-W559+075.WO

• Wossner Piston Kit No.: 8118D075

• Lock: CW16

• Pin: WP036

• Ring Set: RSB5675

Vehicle Fitments

• Yamaha YZ125 1986

• Yamaha YZ125 1987

• Yamaha YZ125 1988