Description

Yamaha YFZ 450R Engine Rebuild Service

The Yamaha YFZ 450R is built to rev, pull hard, and take abuse. However, when the engine starts losing compression, shifting poorly, or feeling weak under throttle, it needs more than a quick patch. A full rebuild brings it back the right way.

At REV6, we tear your engine down completely, inspect every key component, and rebuild it with corrected clearances and refreshed internals. As a result, your YFZ 450R gets sharper response, smoother operation, and the strength it needs for aggressive riding.

Core Requirement

Core required: This is a build core engine service. You send in your Yamaha YFZ 450R engine, and we rebuild it here at REV6.

Before shipping, remove your exhaust, fuel-related components, electrical parts, and sensors. Once your engine is packed, we coordinate pickup and handle the rebuild process from teardown to return shipping.

For step-by-step shipping and prep instructions, visit our Help Center.

If you want to spread out the cost, check out our flexible payment options to keep your rebuild moving.

What’s Included in the Rebuild

• Motor fully cleaned, blasted, and prepared for assembly
• Cylinder head inspected and decked for a proper compression seal
• Camshaft lobes and journals cleaned and polished
• Cylinder inspected for wear and damage
• Worn cylinders replaced with refurbished, hone-finished Nikasil-coated cylinders
• New moly-coated piston, rings, wrist pin, and circlips installed
• Crankshaft bearings cleaned and inspected
• Crankshaft rebuilt as needed
• Complete transmission gearbox and shift assembly inspected and rebuilt
• Clutch assembly fully inspected
• Bottom-end bearings cleaned and inspected
• Oil pump assembly inspected and rebuilt
• Engine cases inspected and machined as needed
• Cases tested for journal wear, cracks, holes, or excessive wear
• Quality control inspection completed before shipping

Note: Final build details may vary depending on your Yamaha YFZ 450R engine’s condition. Damaged components that require replacement may add cost.

Built for High-Rev ATV Performance

The YFZ 450R needs clean shifting, strong compression, and dependable oiling when you ride hard. Because of that, we focus on the top end, bottom end, transmission, clutch, oil pump, and case condition during the rebuild.

In turn, your rebuilt engine delivers stronger response, smoother shifting, and more confidence when you’re back in the throttle.

Warranty & Support

Every REV6 engine rebuild includes a 1-year warranty. In addition, you can upgrade to a 2-year no-fault warranty for $450.

Review coverage details in our warranty policy, browse common questions in our FAQ, or contact our team before ordering.

For first-start guidance, follow our engine break-in procedure. You can also visit the REV6 Blog or watch rebuild content on our YouTube channel.

Looking for Parts Instead?

If you don’t need a full engine rebuild, you can find top and bottom end kits, transmissions, cylinders, pistons, rings, crankshafts, gaskets, seals, valves, clutch parts, ECU tune options, and more in our Yamaha YFZ parts catalog.

Take Action

If your YFZ 450R is losing power, shifting rough, or showing signs of internal wear, now’s the time to rebuild it the right way.

Get back on the trail with sharp response, strong pull, and confidence in your rebuilt engine.

We proudly support veterans and active servicemembers with available discounts—thank you for your service.