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OEM & Performance ATV, UTV & Dirt Bike Parts for Yamaha, Honda, Polaris, Can-Am & More — Shipped Fast from BPRATV
OEM & Performance ATV, UTV & Dirt Bike Parts for Yamaha, Honda, Polaris, Can-Am & More — Shipped Fast from BPRATV

TRX400EX TRX 400X XR400 87mm Big Bore 11:1 High Comp Piston Stage 2 Hot Cams Kit

by BPRATV
Original price $699.99 - Original price $699.99
Original price $699.99
$799.99
$799.99 - $799.99
Current price $799.99

Complete Honda TRX400EX 416cc big bore rebuild kit with 87mm piston, Stage 2 camshaft, Cometic gaskets, and upgraded components for maximum performance.

BPRATV 87mm 416cc Big Bore Kit 11:1 Piston Stage 2 Hot Cams Honda TRX400EX TRX400X XR400

No one else sells more Honda TRX400EX Big Bore Kits (416cc, 426cc, 440cc) — built with the best parts in the industry — at the best price, in stock, and shipped fast.

📖 Product Description

Take your Honda TRX400EX, TRX400X, or XR400 to the next level with this complete BPRATV 87mm 416cc Big Bore Top End Rebuild Kit. Designed for serious riders and builders, this kit delivers a massive performance upgrade with increased displacement, higher compression, and a Stage 2 Hot Cams camshaft for aggressive power gains across the RPM range.


Featuring a forged 11:1 high compression piston, premium Cometic MLS gaskets, and upgraded internal components, this kit is engineered for durability, reliability, and maximum output. Whether you're rebuilding or upgrading, this is one of the most complete and performance-driven kits available for the legendary Honda 400 platform.

🔥 Key Features & Benefits

  • 87mm big bore cylinder increases displacement to 416cc for major power gains
  • 11:1 forged piston improves compression and throttle response
  • Stage 2 Hot Cams camshaft delivers stronger mid-range and top-end power
  • Cometic MLS head gasket ensures superior sealing under high performance conditions
  • SKF cam bearings upgrade for increased durability and reliability
  • Heavy duty cam chain reduces stretch and improves timing stability
  • Titanium head stud kit provides superior clamping strength
  • Compatible with pump or race gas for versatile performance setups

📦 Product Contents

  • BPRATV 87mm big bore cylinder (1-year warranty)
  • Stage 2 Hot Cams camshaft
  • SKF upgraded camshaft bearings (Both)
  • 87mm 11:1 forged piston (Wiseco / Wossner / CP / or JE)*
  • Piston rings
  • Wrist pin
  • Circlips
  • Cometic top end gasket kit
  • MLS big bore head gasket
  • Viton valve stem seals
  • BPRATV heavy duty cam chain
  • BPRATV Talon titanium cylinder head stud kit
  • NGK spark plug

✅ Compatibility

  • Honda TRX400EX (1999–2008)
  • Honda TRX400X (2009–2014)
  • Honda XR400 / XR400R (1996–2004)

❓ FAQ

  • Q: What displacement does this kit create?

    A: This 87mm big bore kit increases engine size to approximately 416cc.

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

    A: Yes, the 11:1 compression piston is designed to run on pump or race gas.

  • Q: Is this a complete top end rebuild kit?

    A: Yes, it includes the cylinder, piston kit, camshaft, gaskets, seals, chain, bearings, and hardware needed for a full top end rebuild.

  • Q: Are all parts new and ready to install?

    A: Yes, all components are brand new and come in original packaging with applicable manufacturer warranties.

🌟 Why Buy from BPRATV

At BPRATV, our promise is unwavering: The Best Parts. The Best Performance. The Best Price. We specialize in high-performance powersports components trusted by riders and builders who demand reliability and results. Every part is carefully selected for precision, durability, and real-world performance. Trust BPRATV to keep your Honda TRX400EX, TRX400X, and XR400 running at its best, every single time.

Unleash serious power with this 416cc big bore performance kit — order today!

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

BRAPPPPPPPPPP!

© BPRATV LLC

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 vehicles used solely for closed-course, nonroad competition/racing.

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