Athena Forged Racing Piston Kit Ø 71.96 mm is designed for the Athena Big Bore Cylinder, offering high-performance durability and precision engineering. Manufactured using advanced CNC machining for tight tolerances of less than 0.01 mm, this piston is made from a high-performance aluminum alloy with a high silicon content for enhanced strength and reliability. The piston’s smooth profile promotes optimal flow and flame propagation, while certain models feature a molybdenum disulfide coating on the skirt to reduce friction. Engineered and tested in Italy under extreme conditions, this piston kit ensures excellent performance and longevity.

Features

• Forged piston with high-performance aluminum alloy construction


• CNC-machined for dimensional accuracy within 0.01 mm


• High silicon content for strength and durability


• Smooth profile for optimized flow and combustion


• Some models include molybdenum disulfide skirt coating for reduced friction


• Piston rings with low-friction design for improved performance


• Japanese-made piston rings with wear-resistant coatings (PVD or chromium nitride)


• Includes piston, pin, circlips, and piston rings


• Designed exclusively for competitive use

Specifications

• Big End Pin Diameter: 18x13x53.5 mm


• Bore Diameter: 71.96 mm


• Compression Ratio: 16.0:1


• Displacement: 250 cc


• Net Weight: 0.34 kg


• Number of Segments: 3


• Piston Head Type: Domed


• Piston Pin Type: Biconical


• Piston Type: Forged

Cross-Reference OEM Part Numbers

• S4F07200006A Piston Kit 71.95


• S41316257 Rings

Vehicle Fitments

• Yamaha YZ 250 2T (2003-2025)