WOSSNER 57.5mm PISTON KIT YAMAHA YZ125 1986-1988

This Wossner 57.50mm (+1.50 oversize) forged piston kit is designed for Yamaha YZ125 models from 1986 to 1988. Produced in Germany, the piston is built using a forged process for enhanced durability and strength. Its elliptical shape helps maintain a consistent bearing surface during thermal expansion, reducing localised stress and evenly distributing thrust loads to prevent piston collapse. The piston also supports efficient heat transfer from the combustion chamber to the cylinder walls, ensuring reliable performance in two-stroke engines.

Features

• Forged piston for increased structural strength and durability

• Elliptical design provides uniform bearing surface during heat expansion

• Minimises localised pressure and evenly distributes thrust loads

• Supports efficient combustion heat transfer to cylinder walls

• Manufactured in Germany

Specifications

• Bore: 57.50mm

• Actual diameter: 57.44mm

• 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+150.WO

• Wossner Piston Kit No.: 8118D150

• Lock: CW16

• Pin: WP036

• Ring Set: RSB5750

Vehicle Fitments

• Yamaha YZ125 1986

• Yamaha YZ125 1987

• Yamaha YZ125 1988

Majority of our listings are for a direct replacement for your original part.

Our parts are made of quality and are designed to meet or exceed the original OEM Standards.

Our products are often a cost effective alternative to genuine OEM Parts.

Please note: the models of bike we state in our listings are for general guidance only. Please make sure this item will fit your bike before purchasing. Also, we cannot guarantee fitment to any non-UK models.