HPRD YZ125/X 144cc Big Bore Kit (2022-2026) - 58mm Cylinder
Unleash the full potential of your Yamaha YZ125 or YZ125X with the HP Race Development Athena 144cc Big Bore Kit! Transform your bike into a fire-breathing 144cc powerhouse, delivering significantly increased horsepower and torque for superior performance on the track or trail. This kit offers a substantial upgrade over stock, providing the competitive edge you need for motocross, enduro, or aggressive trail riding.
Key Features:
- Massive Power Gains: Experience a significant jump in horsepower (up to 45 HP with HPRD porting!). Stock YZ125 increases from ~33 to 37 HP out-of-the-box.
- Complete Kit: Includes 58mm cylinder, modular head with bronze inner dome, forged piston kit, Ergal 7075 power valves, and complete gasket set.
- Superior Design: O-ring head design for enhanced tuning flexibility.
- Optimized Porting: Athena's expertly designed porting ensures excellent flow characteristics.
- Race-Ready: Engineered for maximum combustion efficiency and reliability under demanding race conditions.
Fitment:
- Yamaha YZ125 (2022-2026)
- Yamaha YZ125X (2023-2026)
Important Note: This kit requires case machining for proper installation. This is NOT a drop-in kit! Professional installation is highly recommended.
We stand behind the quality of our performance parts. This kit is backed by HPRD's commitment to excellence and customer satisfaction. Ride with confidence knowing you're equipped with the best.
We process orders within 1-2 business days. Expedited shipping options allow you to get your parts faster just in time for race day.
Returns are accepted within 30 days of purchase for unused items in original packaging. A restocking fee may apply for special order items.