PISTON KIT 83-87 YZ250 69.25, WOSSNER 8133D125 YAMAHA MX

Wossner forged piston kit designed for Yamaha YZ250 models from 1983 to 1987. This kit features a 69.25 mm bore and is precision-engineered for durability and efficient heat transfer. Its elliptical shape ensures consistent bearing surface contact under thermal expansion, reducing the risk of piston collapse and improving engine performance. Manufactured in Germany, this kit includes all essential components for a reliable rebuild.

Features

• Forged piston construction for increased strength

• Superior heat transfer design for improved thermal performance

• Elliptical piston profile to reduce localised pressure and distribute thrust loads

• Engineered for 2-stroke engine applications

• Made in Germany

Specifications

• Bore: 69.25 mm

• Actual Bore Diameter: 69.19 mm

• Compression Height: 36.00 mm

• Display Volume: 246 cm³

• Stroke: 68.00 mm

• Clearance: 0.06 mm

• Compression Ratio: 2-stroke (Wossner and OEM)

Cross-Reference OEM Part Numbers

• Piston Kit Part No.: 8133D125

• Lock P/N: CW18

• Pin P/N: WP033

• Ring Set P/N: RSB6925 (x2)

• Rod P/N: P2048 (for 1983–1989 models)

• Alternate Part No.: 56-W560+100.WO

Vehicle Fitments

• Yamaha YZ250 (1983–1987)