Big Bore Cylinder Kit, Ø 68 mm -ATHENA- for Yamaha YFZ350 Banshee (1987–2006) and for the Lambretta Lutz engine

Athena Big Bore Cylinder Kit, Ø 68 mm / 392 ccm, for the Yamaha YFZ350 Banshee (1987–2006) and the Lambretta Lutz conversion to a 2-cylinder engine

The Athena Big-Bore cylinder kit was developed to boost the performance of the Yamaha Banshee. The stock 350 ccm displacement increases to 392 ccm (bore 68 mm). This delivers a significant boost in power and torque across the entire RPM range—while maintaining uncompromised reliability.

Scope of Delivery

• 2 high-quality aluminum cylinders with a 68 mm bore and a special nickel-silicon coating (Nickasil/Carbide) for maximum durability 
• Cylinder head with two interchangeable center domes
• Complete piston kits (forged, with molybdenum coating) including piston pins and rings
• Matching gasket set (cylinder head and base gaskets specially developed for Athena kits)
• Installation instructions (also available here under Downloads) 

Technical Specifications

• Bore: 68.00 mm
• Displacement: 392 ccm
• Compression ratio: 11.9:1
• Material: Lightweight special-grade aluminum
• Cooling: Liquid-cooled (LC)

The cylinders feature enlarged water jackets for improved cooling and have been validated by Athena through rigorous dynamometer and road tests. All components are designed to withstand the highest temperatures, pressures, and loads.

Compatible with: Yamaha YFZ350 Banshee 350 ccm (1987–2006) and Lambretta Lutz 2-cylinder conversions with a 58 mm stroke. 

Ideal for anyone who wants to give their Lambretta that Banshee kick.