TRX400EX TRX 400X XR400 87mm Big Bore 11:1 High Comp Piston Stage 2 Hot Cams Kit
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
📖 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.
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© 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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Professional installation by a qualified technician is recommended for best results.
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Notice Regarding Photos: Product photos used in our listings are for example only to show item quality, components, and visual reference. You will receive the correct quantity, size, and fitment for the specific kit listed. Exact brands, finishes, packaging, or small components may vary when equivalent-quality parts are used. Please read the full product description for exact details before purchasing.
Bearing Notice: In some cases, you may receive sealed bearings. If your application requires an open bearing, the seals can be removed when appropriate for the application.
Emissions & Race Use Only: Some products may be exempt from emission standards and requirements under 40 C.F.R. § 1051.620 and/or applicable California law. Certain parts are sold only for use with EPA-certified, purpose-built, nonroad vehicles used solely for closed-course, nonroad competition/racing. Installation may void the vehicle manufacturer's warranty and/or may be illegal in some locations. Buyer is responsible for confirming legal use in their application and location.
Warranty & Liability: Due to the nature of high-performance and racing applications, components may be sold without express or implied warranty of merchantability or fitness for a specific purpose except where specifically stated. BPRATV LLC shall not be liable for special, incidental, or consequential damages including loss of property, equipment, profits, or revenue resulting from sale, installation, or use of these parts. High-performance parts are not DIY items; work should be performed by a qualified, experienced mechanic.
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Specialty Warranties: Certain specialty items, such as Cub cylinders or titanium fasteners, may have separate warranty terms. Any warranty does not cover improper tuning, installation, maintenance, or misuse.
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