PISTON KIT 99-18 YZ250 1-RING, WOSSNER 8217DA 66.40 A

This Wossner piston kit with a 66.40mm bore (actual size 66.35mm) features a single-ring piston designed specifically for Yamaha YZ250 models from 1999 to 2018. Forged in Germany, it offers durability, thermal efficiency, and reduced friction for high-performance two-stroke engines.

Features

• Forged single-ring piston for reduced friction and improved response

• Engineered for efficient heat dissipation to cylinder walls

• Elliptical design distributes load evenly to prevent localised pressure and piston collapse

• Manufactured in Germany for reliability and precision

Specifications

• Bore size: 66.40 mm

• Actual piston size: 66.35 mm

• Display (cm³): 249

• Stroke (mm): 68.00

• Clearance (mm): 0.05

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

• Compression height (mm): 38.00

Cross-Reference OEM Part Numbers

• OLD No. 56-W056.WO.A

Vehicle Fitments

• 1999–2018 Yamaha YZ250

Included Components

• Piston: Wossner PN# 8217DA (Single ring)

• Gasket: PN# D2041

• Lock: PN# CW18

• Pin: PN# WP033

• Ring Set: PN# RSB6640

• Rod: PN# P2028