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Athena Big Bore Cylinder & Exhaust Valve Kit 72mm Bore For Yamaha YZ250 2003-2026
The Yamaha YZ 250 has long been a benchmark in motocross performance, delivering explosive power and unmatched agility. For riders seeking a radical upgrade, Athena introduces the Big Bore Cylinder Kit, engineered to transform your YZ 250 into a race-ready powerhouse.
Engineered Evolution for Extreme Performance
This latest version of the Big Bore kit marks a significant evolution over its predecessor. Every component has been redesigned and optimized to deliver more horsepower, enhanced reliability, and sharper throttle response across the entire RPM range.
Redesigned Cylinder: New Port Timing, More Thrust
The aluminum cylinder has been completely re-engineered with a new port timing layout, designed to improve gas flow and maximize combustion efficiency. Internal geometries are optimized to deliver stronger mid-to-high RPM performance while maintaining smooth low-end power.
Recessed Head Design: Precision and Control
The newly recessed cylinder head is the result of advanced engineering. Improved shape and volume enhance squish and compression ratio, ensuring more efficient combustion and smooth, controlled power delivery. The result is a more precise ride with instant throttle response.
Cast Piston: Lightweight and High-Performance
The new lightweight cast piston reduces reciprocating mass and improves engine responsiveness. This translates into quicker acceleration and reduced vibration, offering a cleaner and more aggressive riding experience.
Optimized Exhaust Valves: Aggressive Power, Smooth Torque
The completely redesigned exhaust valves contribute to a more aggressive exhaust timing, delivering stronger top-end power while preserving low-end torque. This ensures optimal control and performance in every riding condition.
Complete Kit: Easy Installation, Total Reliability
As with all Athena cylinder kits, the Big Bore kit includes a high-quality gasket set, built to withstand the harshest racing conditions. Every component is designed for perfect sealing and long-lasting engine durability.
The Ultimate Upgrade for Your Yamaha YZ 250
The Athena Big Bore Cylinder Kit for Yamaha YZ 250 is more than just a replacement—it's a statement of raw power and uncompromising reliability. With this kit installed, every corner becomes an opportunity, and every twist of the throttle delivers pure adrenaline.
With Athena, your YZ 250 becomes the ultimate weapon on the track—ready to respond with surgical precision and unleash unstoppable force.
Description:
- Redesigned cylinder with new port timing
- Recessed head design for efficient combustion
- Lightweight cast piston for better throttle response
- Optimized exhaust valves for aggressive power delivery
Brand: Athena
Part Number: P400485100104
Fitment:
- Yamaha YZ250 2003-2026
Note: Image is for reference only, actual product may vary slightly.
