04/07 450 Engine Case Fitment

My freind has an 07 YZ450. We're riding this weekend when he landed a jumped and the rear hub exploded. The chain packed in around the front sprocket and it destroyed the left case half. I found an 04 left case half on ebay, and needed to know if 04 is the same as an 07. If not what years will interchange. I tried the search option to no avail. Any info is appreciated.

To start with, no, the '03-'05 YZ450 crankcase is not interchangeable with any '06-'09 model, or anything else, for that matter.

Secondly, one should NEVER mix crankcases from another set. They are manufactured and sold in pairs only because the shaft bores are machined with the cases bolted together to ensure absolute concentricity. They should not be mixed under any circumstance.

As to which cases do interchange, '06-'09 YZ450 are a certain direct fit, and as far as I know, the cases from a '07-'09 WR450 can also be used, but don't take that as hard info.

Thanks for the info. He's depressed right know so I'm getting the ball rolling. Once he gets the parts I'll help him with the work. It also took out his swing arm too. Thanks again for the info.

Hey Monty,I'm feeling the same blues. My boy-Brad was riding at Angleton MX on his YZ450 yesterday,and locked up his transmission after landing from a jump.I pulled the motor taday,and will have to split the cases.Let me know if your buddy decides to buy a complete motor,as I will need a transmission I suppose.His is an 07 450.

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