YZ450F - Back from the dead

A few weeks ago, I traded a '00XR100 for a basket case '04 YZ450F that had been sitting around a guy's garage for a while. It looked to be in decent shape and all the parts were there, so why not. It did have a little problem:



Rather than try to fix the broken case, I found a complete new bottom end for $400 on eBay that was in really good shape. Using the replacement bottom end, I bolted up the motor and over the weekend stuffed it all into the frame. Turns out I was missing some oil lines, but eBay came through there as well. I gassed the bike up on Sunday. It started after about 6 kicks. Just running it up and down the street, the thing rips. No bog, idles nice and seems to have crazy power. Needs a few odds and ends like bark busters, but looks like a nice addition to the stable. :thumbsup:




Anyone need some '04 motor parts? I've got everything except a right case half. :confused:

Nice trade.! Did someone try to tig weld the case?

Nice trade.! Did someone try to tig weld the case?

Yes. The story on that is that the guy I got it from traded a YZ250 two-stroke to get the 4-stoke. First or second ride out he noticed a bunch of oil spewing out from the motor and stopped riding. That's when he discovered the broken case. Apparently the previous owner had welded the case and it worked for a while, but ultimately didn't hold.

I was going to fix it by having a machinist make a new bushing for the kick starter shaft and then TIG welding it in place, but getting a ready-to go-bottom end made the job a lot easier, and hopefully I can sell the parts on eBay.

Looks nice:thumbsup:

BTW. This is a great forum. Tons of valuable info that helped me get this machine put back together and from what I can tell working pretty well. This was my first go-round with a 4-stroke. Since my other bike is a YZ250 smoker, the basic design approach was familiar. The biggest learning curve was on the top end, but there are some subtle differences here and there.

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