PISTON KIT YAM 350 R5 65.25, WOSSNER 8221D125

This piston kit is intended for Yamaha 350 R5 motorcycles from 1973 to 1975 and features a single forged Wossner piston with a +1.25mm oversize (65.25mm bore). The piston is elliptically designed for improved thermal expansion characteristics and even load distribution, reducing the chance of mechanical failure under stress. Manufactured in Germany, this kit is optimised for two-stroke engine reliability and performance.

Features

• Single forged Wossner piston

• +1.25mm oversized bore (65.25mm, actual piston diameter 65.18mm)

• Elliptical design for uniform thrust load distribution

• Enhanced heat dissipation to cylinder walls

• Made in Germany

Specifications

• Part Number: 8221D125

• Bore Size: 65.25mm (actual piston size 65.18mm)

• Oversize: +1.25mm

• Displacement: 347cm³

• Stroke: 54.00mm

• Clearance: 0.07mm

• Wossner Compression Ratio: 2-stroke

• OEM Compression Ratio: 2-stroke

• Compression Height: 36.00mm

Cross-Reference OEM Part Numbers

• Clips: CW16

• Piston Pin: WP027

• Rings: RSB6525 x 2

Vehicle Fitments

• Yamaha 350 R5 1973–1975