Athena YFZ450 98 mm Big Bore Cylinder Kit – 478 cc (2004–2009)
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
📦 Shipping Information
In-Stock Items:
- Most parts ship next business day
- Modquad parts: Monday–Thursday dispatch
Made-to-Order Items:
- Custom swingarms & A-arms: 2–4 weeks
- EVP exhaust systems: 2–4 weeks
- Sneakers: 1–2 weeks
Stock Guarantee: Items marked "In Stock" ship immediately. Made-to-order items are built fresh for you.
Questions? Contact us—we respond within 24 hours.