2005+ TRX 400EX 400X Full Top Bottom End Engine Rebuild Set Forged Piston Crank
Complete top and bottom end rebuild kit for 2005+ Honda TRX400EX and 400X. Includes forged piston, crankshaft, bearings, seals, clutch kit and titanium studs.
2005+ Honda TRX400EX 400X Complete Engine Rebuild Kit – Top & Bottom End
📖 Product Description
Give your quad a full performance overhaul with the BPRATV Complete Top & Bottom End Engine Rebuild Kit for 2005+ Honda TRX400EX and 400X models. This all-in-one motor assembly set includes premium forged internals, upgraded valvetrain components, complete gasket and seal kits, and heavy-duty drivetrain upgrades to rebuild your engine the right way — the first time.
Whether you're restoring a worn-out engine or building a stronger, more reliable trail or track machine, this kit delivers improved durability, smoother power delivery, and high-revving performance that outlasts stock components.
🔥 Key Features & Complete Kit Contents
Every major wear component from the crankshaft up is included for a true full motor rebuild.
- New aftermarket 85mm stock bore cylinder
- Forged piston (Wiseco, Wossner, CP Carrillo, or JE based on availability)
- Nitrite-coated piston rings
- Chrome wristpin and circlips
- Hot Rods or Wiseco crankshaft with connecting rod (based on availability)
- Main crank bearings
- Complete transmission bearing set
- Talon Titanium head stud kit
- Complete gasket kit including MLS head gasket, base gasket, intake, exhaust, case, clutch cover, pump covers, and O-rings
- Complete crankcase oil seal kit
- BPRATV Heavy-Duty cam chain conversion (wider than OEM chain)
- BPRATV Talon clutch kit
- NGK spark plug
✅ Compatibility
Designed specifically for late-model Honda 400 platforms.
- Honda TRX400EX – 2005 and newer models
- Honda TRX400X – All years (2009+)
- Air-cooled 397cc Honda 400 engine platform
- Stock bore 85mm configuration
- Compatible with pump gas or race gas setups
❓ Frequently Asked Questions (FAQ)
- Q: Is this a complete top and bottom end rebuild kit?
A: Yes. This kit includes cylinder, piston assembly, crankshaft, bearings, seals, gasket kit, cam chain, clutch kit, and ignition components for a full engine rebuild.
- Q: Which piston and crank brand will I receive?
A: Forged pistons may be Wiseco, Wossner, CP Carrillo, or JE. Crankshafts may be Hot Rods or Wiseco depending on inventory. You may contact us with a preference, but we cannot guarantee a specific brand — only what is in stock at the time of shipment.
- Q: Is this stock bore or big bore?
A: This kit uses a new 85mm stock bore cylinder, making it ideal for reliable performance rebuilds without displacement increase.
- Q: Is there a warranty included?
A: Yes. This rebuild kit includes a 1-year limited warranty* covering manufacturer defects.
🌟 Why Buy from BPRATV? Honda 400 Performance Experts 🌟
At BPRATV, our promise is unwavering: The Best Parts. The Best Performance. We specialize in complete Honda 400 engine builds using proven forged internals and upgraded components that outperform stock parts in durability and reliability. Trust BPRATV to keep your Honda TRX400EX or 400X running at its best, every single time.
Rebuild it right. Ride harder. Order your complete engine kit today!
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 [e.g., vehicle code §§ 27156 and 38391]. This product is sold only for use in connection with EPA-certified, purpose-built, nonroad vehicles used solely for closed course, nonroad competition/racing and not used for any recreational purpose or on public highways or rights of way maintained by and open to the public. This product is sold only in connection with machines that do not fall under state and/or federal noise or emission standards/regulations. Purchasers who purchase this product represent and warrant that the product is purchased only in connection with EPA-certified, emission-regulations-exempt and noise-regulations-exempt competition/racing vehicles as interpreted under applicable state and/or federal law.
Complete Your Build
Related parts, upgrades, and performance accessories frequently purchased by riders like you.
Professional Installation Required
Professional installation by a qualified technician is recommended for best results.
If you have questions about this item or your order, our customer support team is always happy to help.
BPRATV: Over 20 Years of Excellence in Parts & Service
Upland, CA | Monday - Friday, 7 am - 4 pm PST
We ship worldwide Monday through Friday | ¡Hablamos Español!
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.
Returns: Returns are accepted within 30 days for eligible items that are 100% complete, brand new, unused, uninstalled, and in original packaging. Items that have been installed, prepped, lubricated, sealed, modified, or used are not eligible. For warranty consideration, parts must be sent back for physical inspection. We do not warranty based on photos, emails, or third-party assessments.
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.
Interchangeable Parts: Some kits may include interchangeable components or equivalent-quality substitutions to prevent backorder delays. Prices, included items, and listings are subject to change without notice.
Customer Satisfaction: If you experience any issue with your order, please contact us through eBay Messages before leaving feedback. Our team is committed to resolving any concerns quickly and professionally.
© BPRATV LLC