PISTON KIT YAM XS650 77.00, WOSSNER K8818D200-2 688cc

This piston kit is designed for Yamaha XS650 motorcycles manufactured between 1974 and 1981. It includes a set of four Wossner forged pistons with a +2.00mm oversize (77.00mm bore), offering enhanced durability and performance for overbored engine configurations. The pistons feature an elliptical design that ensures even thrust load distribution and superior heat expansion management. Manufactured in Germany, this kit maintains OEM compression characteristics and fits within the standard displacement range.

Features

• Set of 4 forged Wossner pistons

• +2.00mm oversized bore (77.00mm, actual piston diameter 76.94mm)

• Elliptical construction for consistent load distribution and thermal stability

• Designed to improve combustion heat transfer to cylinder walls

• Made in Germany

Specifications

• Part Number: K8818D200-2

• Bore Size: 77.00mm (actual piston size 76.94mm)

• Oversize: +2.00mm

• Displacement: 679 / 688cm³

• Stroke: 74.00mm

• Clearance: 0.06mm

• Wossner Compression Ratio: OEM

• OEM Compression Ratio: 8.40:1

• Dome Volume: +23.40cm³

• Compression Height: 29.00mm

Cross-Reference OEM Part Numbers

• Clips: CW20

• Piston Pin: WP068

• Rings: 770XDS

Vehicle Fitments

• Yamaha XS650 1974–1981