XR400 XR 400R 89mm Big Bore Kit +4 Cylinder Hi Comp Top End Rebuild Stage 3 Cam
Upgrade your Honda XR400R or TRX400EX with an 89mm big bore top end rebuild kit featuring a forged piston, Stage 3 Hot Cams camshaft and Cometic MLS gaskets.
Honda XR400 XR400R 400EX 400X 89mm +4 Big Bore Cylinder Hi Compression Top End Rebuild Kit Stage 3 Hot Cams
📖 Product Description
Transform your Honda engine with this 89mm +4 Big Bore Top End Rebuild Kit featuring a brand-new aftermarket cylinder, a forged Wiseco or CP Carrillo high-compression piston, and a performance Stage 3 Hot Cams camshaft. Designed for riders looking to maximize horsepower, throttle response, and overall engine performance, this complete kit delivers everything needed for a premium top-end rebuild.
Engineered to fit all Honda XR400R, TRX400EX, and TRX400X models and years with no modifications required, this package combines race-proven components from industry-leading manufacturers for outstanding durability, reliability, and performance. The high-compression piston provides increased power while maintaining compatibility with pump or race gas.
🔥 Key Features & Benefits
- 89mm (+4mm) big bore cylinder increases displacement and horsepower.
- Wiseco or CP Carrillo forged piston for superior strength and durability.
- High-compression piston delivers stronger torque and faster throttle response.
- Stage 3 Hot Cams camshaft maximizes mid-range and top-end power.
- SKFOEM upgraded cam bearings improve reliability and camshaft support.
- Cometic MLS head gasket provides exceptional sealing for high-performance applications.
- Heavy-duty timing chain ensures accurate valve timing and long service life.
- Direct bolt-on installation with no engine modifications required.
- Compatible with pump gas or race gas.
📦 Product Contents
- 89mm (+4mm) aftermarket big bore cylinder
- Wiseco or CP Carrillo forged high-compression piston
- Nitride-coated piston rings
- Chrome wrist pin
- Piston circlips
- Stage 3 Hot Cams camshaft
- SKF OEM upgraded camshaft bearings
- Cylinder head studs
- Cometic complete top end gasket kit
- Cometic MLS head gasket
- Heavy-duty timing chain
✅ Compatibility
Designed as a direct-fit performance upgrade for the following Honda models:
- Honda XR400R - All Years
- Honda TRX400EX - All Years
- Honda TRX400X - All Years
- Direct bolt-on installation with no machining or modifications required.
❓ Frequently Asked Questions
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Q: Does this kit require machining or engine modifications?
A: No. This kit is designed as a direct bolt-on upgrade for all compatible models with no additional modifications required.
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Q: Which piston brand is included?
A: The kit includes either a Wiseco or CP Carrillo forged piston depending on current inventory. Both are premium performance pistons manufactured to the highest standards.
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Q: Can I run pump gas?
A: Yes. This combination is designed to operate on pump gas or race gas when properly tuned.
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Q: What benefits does the Stage 3 Hot Cams camshaft provide?
A: The Stage 3 camshaft significantly improves airflow, throttle response, mid-range power, and top-end horsepower for aggressive riding and racing applications.
🌟 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 XR400R, TRX400EX, or TRX400X running at its best, every single time.
Build bigger power and legendary Honda reliability--order your 89mm Big Bore Stage 3 Top End Kit 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.
