Description

Honda 400EX Engine Rebuild Service

This is a core-based rebuild service for your Honda 400EX engine. You send in your engine, and it gets rebuilt from the ground up. As a result, worn parts get corrected, and your machine runs strong and consistent again.

What Your Engine Rebuild Includes

• Standard No-Fault 1-year warranty with optional 2-year no-fault upgrade
• Full teardown, cleaning, inspection, and rebuild of all components
• Precision machining where needed to restore proper clearances

Top End Work

• Inspect and deck the cylinder head for a proper seal
• Clean and polish camshaft lobes and journals
• Bore and hone the cylinder to factory specifications
• Install new moly-coated piston, rings, wrist pin, and circlips

Bottom End & Internal Components

• Inspect crankshaft bearings and rebuild as needed
• Check and verify all bottom-end bearings
• Inspect and machine engine cases, then check for cracks or wear

Transmission & Oil System

• Inspect and rebuild the transmission gearbox and shift assembly
• Inspect the clutch assembly and correct any issues
• Inspect and rebuild the oil pump assembly

Note: This is a standard rebuild process. However, the final build may vary depending on the condition of your engine. If damaged parts require replacement, additional costs may apply.

Core & Shipping Process

This service requires your engine core. First, place your order to secure your rebuild spot. Then, follow the provided instructions and remove external parts like exhaust, electrical, and fuel components. After that, package your engine and send it in using the provided label.

Once your engine arrives, the rebuild begins. Typically, turnaround time is about 2 weeks. After final inspection, your rebuilt engine ships back ready to install.

Quality Control & Inspection

Each engine goes through multiple checks. First, the builder verifies all measurements. Then, a second inspection confirms tolerances and assembly. Because of this process, the engine is ready to perform.

Warranty & Support

Every engine includes a 1-year no-fault warranty. In addition, you can upgrade to a 2-year no-fault warranty for extra protection.

For full details, review our engine warranty coverage. If you have questions about your build, visit our contact page.

For setup tips, check the engine break-in guide. You can also explore the REV6 Blog, browse the FAQ, or view more options in the Honda ATV section.

Take Action

Send in your core and get your Honda 400EX engine rebuilt the right way. With nationwide shipping and a proven process, getting back to riding is simple.