Athena Big Bore Race Cylinder Kit – 98 mm (478 cc) – Yamaha YFZ450 (2004–2009)

Take your YFZ450’s performance to the next level with the Athena 98 mm Big Bore Race Cylinder Kit. Featuring race-engineered components and precision nickel-carbide coating, this kit delivers more displacement, stronger power throughout the RPM range, and unmatched durability for aggressive riding.

✅ What’s Included

• 98 mm (478 cc) Big Bore Aluminum Cylinder

• Nickel-Carbide Cylinder Bore Coating

• Forged Molybdenum-Coated Piston

• Piston Rings

• Wrist Pin & Circlips

• High-Performance Power Valves (hard anodized)

• Installation Instructions

⚙️ Key Features & Benefits

• More Power & Torque – Boosts displacement to 478 cc for instant low-end and midrange gains

• Race-Spec Cylinder – Nickel-carbide coating ensures reliability under high heat and RPM

• Precision Water Jackets – Improved cooling capacity for sustained hard riding

• Forged Piston Design – Lightweight yet strong for maximized throttle response

• Easy Bolt-On Upgrade – No machining required; fits directly to OEM bottom end

• Compression Ratio 12.0–12.4 : 1 – Optimized for pump or race fuel

(Cylinder head not included.)

📦 Compatibility

• Yamaha YFZ450 (2004 – 2009)

🛡️ Warranty Info

1-year manufacturer warranty against defects.
Professional installation and proper break-in required for coverage.

💲 Price: $820.95 (Suggested Retail)
🔢 SKU: 0931-0022 / P400485100016
🏷️ Brand: Athena