Description

Yamaha Grizzly 400 Engine – Core Build Rebuild Service

If your Yamaha Grizzly 400 engine has lost compression, developed noise, or started burning oil, it’s time for a full rebuild. We take your original engine core, tear it down completely, machine it to proper specifications, and rebuild it for dependable performance.

This is a core build engine. You send us your engine, and we rebuild and return it ready for work or trail use. We also offer nationwide shipping to make the process simple.

Warranty Coverage

Every rebuilt Grizzly 400 engine includes a standard 1-year no-fault warranty. In addition, you can upgrade to a 2-year no-fault, no-questions-asked warranty for an additional $450. With the upgraded plan, we replace your engine free of charge if anything happens during the coverage period.

For complete coverage details, visit our engine warranty page.

What Your Engine Rebuild Includes

• Complete teardown, cleaning, and inspection of all components
• Refurbished crankshaft
• Cylinder inspected, bored and honed to next oversize or replaced
• New piston and piston rings
• Cylinder head cleaned, decked, and rebuilt to manufacturer specifications
• Valve guides inspected and replaced as needed
• Valves and seats recut and verified with vacuum testing
• Camshaft lobes and journals cleaned, polished, replaced if required
• Timing chain inspected and replaced as needed
• Refurbished oil pump assembly
• Engine cases inspected for cracks or excessive wear
• All gaskets and seals replaced
• Final assembly torqued to manufacturer specifications

Why Proper Remanufacturing Matters

First, correct cylinder machining ensures proper ring seating. Next, valve refacing restores compression and prevents leakage. In addition, accurate torque procedures protect internal clearances and long-term durability. Because we follow strict rebuild standards, your Grizzly 400 engine returns ready for reliable service.

Core Requirement

A rebuildable engine core is required before shipment. Once we receive your engine, we complete the rebuild process and return it to you.

Before shipping your engine, review our core shipping instructions for packaging and freight details.

Need Assistance?

If you have fitment or rebuild questions, visit our help center or contact our team directly through our support page.

For break-in procedures and engine education, explore the REV6 blog.

If your Grizzly 400 is ready for fresh power, send in your core and rebuild it the right way.