YFZ450R / YFZ450X Complete Engine Rebuild Kit – OEM Crankcases + Stock Bore

Fits All Yamaha YFZ450R & YFZ450X Models (2009–2019)
Everything you need to fully rebuild your YFZ450R or YFZ450X motor—featuring brand new OEM crankcases, a forged piston, and a complete matched rotating assembly. Built for racers and riders who want a fresh start with OEM-quality components.

✅ What’s Included

• Brand new OEM crankcases

• New aftermarket stock bore cylinder

• Wiseco forged piston + hi-temp rings

• Chrome wrist pin & circlips

• Hotrods or Wiseco crankshaft with connecting rod

• Main, transmission, shift cam, and crank balancer bearings

• Clutch arm & water pump bearings

• Full top & bottom end gasket kit (MLS head gasket included)

• Crankcase oil seal kit + valve stem seals

• Water pump shaft, mechanical seal, and impeller

• Brand new oil pump

• K&N oil filter + NGK spark plug

• Timing chain + complete clutch kit

• DuneGoonShop stickers included

• All parts are brand new – Runs on pump or race gas

🔧 Built for Performance

• OEM-Quality Foundation: Start with new crankcases

• Reliable Power: Forged internals and balanced rotating assembly

• Complete Kit: No chasing down missing pieces

• Peak Durability: Internals matched for maximum life

🧩 Fitment – Confirmed Compatibility

Fits ALL YFZ450R & YFZ450X Models:

• YFZ450R (2009–2019)

• YFZ450R SE (2009–2019)

• YFZ450REL (2014 Team Yamaha Edition)

• YFZ450RW (2012–2013 Custom Graphics)

• YFZ450X / XSE (2010–2011 incl. Bill Balance Edition)

🛡️ Warranty & Return Policy

• 1-Year Limited Warranty on qualifying components

• Lifetime warranty on studs (failure during use only)

• Cylinder (Alpha Cub): Replaced or repaired if it fails under normal use

• All warranty claims require return of failed part for inspection

• 30-Day Returns accepted on new, unused parts

• Buyer’s remorse returns subject to 10% restocking fee + shipping deduction

• Professional installation required for warranty coverage