2004 yz 450

So i bought a 2004 yz 450 and the day after i bought it the kick start gear broke in half and went through the top of the engine case. So now i'm trying to find a used engine case. I talked to the dealer and they told me i had to buy them as a pair. I started looking into it and I've read that the yz450 has interchangable parts with the yfz 450. I was wondering if the engine case would be interchangable? I assume i would have to get a kick start gear and have that put in. Any information would help.

Thanks in advance

The Gen1 ('03-'05) YZ450 cases are not interchangeable with any other Yamaha product.

Have you been told by a good machinist/TIG welder that it's not repairable?

I talked to a few welders that told me it was pop metal. Not sure what that is. They said they can't weld it but there was another type of weld possible. but it never holds and it's not worth trying. Now were thinking about J and B welding it. Also not to sure what that is. They said that could work since there it doesn't hold oil it just gets oild splashed on it. I'm not sure what i should do.

OK, now you know a couple of welders not to talk to. The cases are not "pot metal", they are aluminum, and it takes special skills and machinery to weld it, but it can be done. You need to have this looked at by a good custom machist with a TIG welder.

JB weld is a hardware store grade two part epoxy that does have its uses, and could even be helpful here, but I wouldn't bet on it.

It can definately be welded (see user name). Post a pic, lets see the damage.

Okay when i go home this weekend i'll get a picture of it. Theres two triangled sized pieces that came off. We have all the pieces.

I really didn't want to J and B weld because i heard it doesn't always hold.

Thanks a lot

definately post a picture. I weld aluminum often and those other welders you talked to are lazy or just inexperieced(welders that are mediocre usually dont want to work on anything that might test thier skills). Check ebay often and post pictures of the damage, also the crankcase assembly can be had at the thumper store for about $480. Sorry dude that sucks that it broke the second day. Good luck:thumbsup:

I just had a 2.5 inch long by 1.25 inch wide hole in the bottom of my case welded up. Plus he had to weld in one of the bolt holes that had been broken out and still attached to the bolt. I did not even have the pieces that broke out. First I die ground the hole square and then made a piece of aluminium to fit the hole. Had an awsome welder buzz it up for $150 finished to fit nice. As long as it doesn't leak I am happy. He said it was his first Yamaha cast aluminum welding job and it welded great with no problems. Your fix should be no prob.

Moral of the storey keep welder shopping. You have all of your pieces, look for a welder who specializes in aluminium it is worth any extra $$. Good used cases go for around $300 on ebay....I have been watching since December.

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