Yamaha YFZ450R 98mm 478cc Big Bore Top End Kit CP Piston Cometic 13.5:1 EFI NEW!

Yamaha YFZ450R / YFZ450X 98mm 478cc Big Bore Top End Kit CP Cometic 13.5:1

📖 Product Description

Transform your EFI Yamaha with the BPRATV 98mm 478cc Big Bore Top End Kit engineered for riders who demand aggressive power, instant throttle response, and proven durability. Built around a forged CP-Carrillo piston, a performance-plated BPRATV Nikasil cylinder, and a precision Cometic MLS gasket, this kit boosts displacement to 478cc with a race-focused 13.5:1 compression ratio for explosive performance.

🔥 Key Features & Benefits

Designed as a complete, race-ready solution, this big bore kit delivers reliable power gains with OEM-plus fit and finish for high-performance riding and competition use.

• 98mm big bore increases displacement to 478cc for massive torque gains
• 13.5:1 compression for harder hit, stronger midrange, and top-end pull
• CP-Carrillo forged piston for high-RPM stability and long service life
• Nikasil-plated cylinder for superior heat transfer and wear resistance
• Cometic Top End Gasket Kit with a Big Bore Cometic MLS gasket ensures reliable high-pressure sealing

✅ Compatibility

Precision-engineered for Yamaha fuel-injected 450 sport ATVs using a direct big bore replacement top end.

• Yamaha YFZ450R EFI – 2009–2026
• Yamaha YFZ450X EFI – All Years
• Replaces OEM top end with 98mm big bore components
• Designed for race fuel use due to high compression
• Professional installation and EFI tuning recommended

❓ Frequently Asked Questions (FAQ)

• Q: Do I need tuning after installing this kit?

  A: Yes. EFI fuel and ignition mapping must be adjusted for the 98mm 478cc setup.

• Q: Will this work with a stock cylinder head?

  A: Yes. It is designed to run with a healthy stock head and valves.

• Q: Can I run pump gas with this kit?

  A: No. Due to the 13.5:1 compression ratio, race fuel is required.

• Q: What warranty is included?

  A: The cylinder includes a 1-year limited BPRATV warranty; other components carry manufacturer warranties.

🌟 Why Buy from BPRATV? Trusted Performance Experts 🌟

At BPRATV, our promise is unwavering: The Best Parts. The Best Performance. The Best Price. Every kit is carefully selected and built to deliver proven power, precise fitment, and race-level reliability. Trust BPRATV to keep your Yamaha YFZ450R/X running at its best, every single time.

Upgrade your YFZ today and feel the 478cc difference on your next ride.

BPRATV - The Best Parts. The Best Performance. The Best Price.

BRAPPPPPPPPPP!

© BPRATV LLC 1-year limited warranty from the manufacturer for material or workmanship defects.*

Due to the nature of high performance and racing applications, BPRATV LLC components are sold without express warranty or any implied warranty of merchantability or fitness for a specific purpose. BPRATV LLC shall not, under any circumstances, be liable for any specific, incidental or consequential damages, including, but not limited to, damage, or loss of property or equipment, loss of profits or revenue(s), cost of purchased or replacement goods, or claims of customers of the purpose, which may arise and/or shall result from sale, installation or use of these parts. Installation of these parts may void vehicle manufacturers warranty coverage and/or may cause the vehicle to be illegal in some locations.

This product is exempt from the emission standards and related requirements of 40 C.F.R. § 1051 as provided by 40 C.F.R. § 1051.620, and California law. This product is sold only for use in connection with EPA-certified, purpose-built, nonroad competition vehicles and is not legal for use on public highways.