Athena launches new Big Bore Cylinder Kit for Yamaha YZ 125 2022-2024

Alonte (VI), Italy, January 2025. Athena, with over 50 years of experience in high-performance motorcycle parts, presents the new Big Bore Cylinder Kit, designed to maximise the performance of the Yamaha YZ 125 (2022-2024 models).

This innovative kit, which increases displacement to 144 cc, delivers explosive power from the very first twist of the throttle. Through rigorous dyno and track testing, the kit has been refined to ensure a significant power boost and enhanced reliability, essential for riders aiming for peak performance. The kit configuration guarantees immediate response and progressive thrust across the entire RPM range, making every acceleration a pure adrenaline rush. All components of the kit have been internally designed and developed to ensure optimal synergy, providing maximum reliability and durability.

OPTIMIZED CYLINDER

The aluminum cylinder is engineered with optimized geometry to maximize combustion efficiency. The intake and exhaust ports are designed for ideal gas flow, while the water jackets prevent overheating. The result is smooth, balanced power delivery with consistent performance across the entire RPM range.

MODULAR HEAD

A standout feature of this kit is the modular head, composed of an aluminum outer shell and a bronze inner dome. This design allows precise customization of squish and compression ratios, improving heat dissipation, reliability, and durability. The self-centering dome, recessed into the cylinder, enhances combustion and ensures a perfect seal.

ERGAL 7075 EXHAUST VALVES

The valves, crafted from Ergal 7075 with hard anodizing, offer high thermal resistance and optimal lightness. Their precision seal prevents compression losses, maintaining consistent power.

GASKET KIT

Athena’s Big Bore Cylinder Kit also includes a complete gasket set, engineered to withstand the extreme conditions of the track and provide a perfect seal.

With the launch of the new Big Bore Cylinder Kit, Athena reaffirms its commitment to innovative solutions for the offroad market, offering professionals an exclusive performance upgrade for the Yamaha YZ 125, capable of meeting even the most demanding riders’ needs.