PISTON KIT SET/4 R1, FZR, RX1, WOSSNER K8840DA-4 YAMAHA

This piston kit is designed for Yamaha R1, FZR, and RX1 models spanning 1999 to 2005. It features a set of four forged Wossner pistons with a standard 74.00mm bore, engineered for high-performance applications. The elliptical design ensures even load distribution under thermal expansion, reducing stress points and improving durability. Manufactured in Germany, this kit offers precise fitment and performance characteristics for 1000cc-class engines.

Features

• Set of 4 forged Wossner pistons

• Standard bore (74.00mm, actual piston diameter 73.95mm)

• Elliptical profile for uniform thrust load distribution and thermal control

• Designed for efficient combustion heat transfer

• Made in Germany

Specifications

• Part Number: K8840DA-4

• Bore Size: 74.00mm (actual piston size 73.95mm)

• Displacement: 1000cc

• Displacement Range Displayed: 998 / 1024 / 1051 cm³

• Stroke: 58.00mm

• Clearance: 0.05mm

• Wossner Compression Ratio: 10.20:1

• OEM Compression Ratio: 11.80:1

• Dome Volume: -2.60cm³

• Compression Height: 22.80mm

Cross-Reference OEM Part Numbers

• Clip: CW17

• Piston Pin: WP083

• Replacement Ring Set: 740XDS

Vehicle Fitments

• Yamaha R1 1999–2003

• Yamaha FZR 1999–2003

• Yamaha RX1 2001–2005