Cylinder Works Cylinder Head CH2005-K01 — Yamaha YZ125 2005-2021

Product Description

Unlock the potential of your Yamaha YZ125 with the Cylinder Works Replacement Cylinder Head. Designed for riders who demand more from their 2-stroke engine, this high-performance component features a professional competition valve job, shortened valve guides to accommodate higher lift camshafts, and an unshrouded combustion chamber for optimized airflow. This head is precision-engineered to provide a significant upgrade over stock components, delivering improved power and responsiveness across the entire rev range.

Each Cylinder Works head is manufactured in the USA, ensuring strict quality control and exceptional craftsmanship. The design includes a blended bowl seat-to-port transition to maintain smooth airflow, all while retaining a stock-shaped port geometry for easy integration into your existing setup. Please note that this is a bare cylinder head—it does not include valves, springs, or lifters, allowing you to customize your build with the valvetrain components of your choice.

Top Features: Cylinder Works Cylinder Head

• Professional-grade competition valve job for enhanced performance
• Shortened valve guides optimized to accept higher lift cams
• Unshrouded combustion chamber design for maximum efficiency
• Blended bowl seat-to-port transition for improved flow characteristics
• Manufactured in the USA to the highest quality standards

Please review the detailed compatibility data below to ensure an exact fitment match for your motorcycle before finalizing your purchase.

Fitment List

Frequently Asked Questions

Q: Does this head come ready to bolt on?
A: This is a bare cylinder head. It does not include valves, springs, or lifters. You will need to transfer your existing valvetrain or install new performance components before bolting the head onto your engine.

Q: Is this compatible with a stock YZ125?
A: Yes, it is designed for standard bore Yamaha YZ125 engines, but its performance-oriented features (like the competition valve job and unshrouded chamber) are specifically engineered to provide better results than a stock head.

Expert Pro-Tip

Expert Pro-Tip: Whenever you swap a cylinder head on a 2-stroke, always check your squish clearance with solder to ensure it falls within the manufacturer's recommended specifications for your fuel and compression ratio. Running a head with improper squish can lead to dangerous detonation, which will destroy a YZ125 top end in seconds. Precision here is the difference between a championship motor and a scrap heap.

Recommended Pairings

Recommended Pairings:
o Yamaha 2-Stroke Performance Parts
o Premium Motorcycle Chemicals
o YZ125 Performance Upgrades

About Moto-House MX

At Moto-House MX, we carry the best brands in motocross and off-road performance. Our team has over 40 years of experience helping riders get more out of their bikes. Every order ships fast from our Central Florida location.

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