06' 450 thrown chain broken case pics

51 replies to this topic
  • yzf450jack

Posted June 28, 2006 - 04:45 PM


I am welder and never never JB weld. it contaminates the base metal, eventually falls out. and causes more grief, when a welder goes to weld. the pours are full of glue...and have to be ground out, thus making the base thinner.a good tig welder can weld that up!

Yup he's right aluminum has to be very clean to weld. JB like's to pop hot metal on you then you have to grind all of it out and try again!

  • JaZ

Posted June 30, 2006 - 12:25 AM


Hi Rooster
I had a very similar problem but the missing chunk was much bigger,
(and the case saver does nothing to stop a chain ripping through the case going at 120km/h as I was )

OK LISTEN UP donot use BJ weld I did and it lasted 3 rides before it started leaking.

I was quoted $2000AU to replace cases.

:ride: It ended up costing me $60AU GO TO A VERY GOOD WELDER done a great job

  • steveasba

Posted July 02, 2006 - 05:45 PM


I had the same thing happen to me. I tried to get it welded but could not find any material that would not stick to the weld. I tried drill bits,carbon steel and stainless steel. I am a machinist and have access to many different type of steel. But could not find anything that worked. The last thing I tried was a drill bit, and with just a spot weld it took 3 days to get it out of the hole.

So I machined a tube out of aluminum. .154 in diameter and drilled a .094 dia
hole thru it. Stuck the tube into the oil port and put J.B. weld over the hole.
I have been out to the track 3 times now and it's working great.

You access the oil port where the clutch arm enters the case. There is a bearing in there that covers up about half of the port. This bearing is a bitch to remove. I ended up destroying the bearing to get it out and just bought a new one. The new bearing went in real easy.

You might want to try this first. A new side case by it's self is $562.00.
You will also need gaskets and maybe some bearings and labor cost if you take it to a shop. It only took me about 10 minutes to make the tube, so any small machine shop in your area should be able to make you one pretty cheap.


  • yogist

Posted July 02, 2006 - 06:16 PM


Im buying a new master link and putting the clip on the inside..!!! What a bummer..Any way you look at it its gonna be a pain in the ass to fix...

  • TexN343

Posted July 07, 2006 - 07:46 PM


Not to HiJack this thread or anything but I have a problem close to this. I have an 04 yz450 with a 16tooth front sprocket. I had to remove the case save to allow this size sprocket. I also have a DID X-ring chain so the clearance between the case and the chain are minimal will this cause any problems. I will get pics soon and show you how close they are.

  • rooster wrooster

Posted July 17, 2006 - 11:30 AM


Update. I had the hole JB welded before I read the posts about not doing it. After it was done, I leak tested it and no leaks. I planned on waiting to the end of the riding season to replace the cases. But I went to ride it a couple of days after it was fixed and it started leaking again. So here is the current state of repair.

Posted Image

You can see in the upper right side of this pic where I attempted to JB weld it.

Posted Image

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  • yamahacrazy_310

Posted July 17, 2006 - 11:38 AM


So how much is that case going for?

  • barch88

Posted July 17, 2006 - 12:12 PM


Looks like you will just have to do it the right way and shove out the cash for new cases + labor (unless you do it all yourself). How is the rest of the case look? I notice chips above the sprocket shaft...

Next time make sure to use a case saver man!

Good Luck.

  • rooster wrooster

Posted July 17, 2006 - 12:53 PM


yamahacrazy_310, its about $600. They have to be bought in pairs.

  • yamahacrazy_310

Posted July 17, 2006 - 02:46 PM


yamahacrazy_310, its about $600. They have to be bought in pairs.

That sucks. but at least you will have a spear. You might get lucky and find one on e-bay. I did with my swing arm.

  • Terrain Rider 4z

Posted July 18, 2006 - 08:18 PM


Had two guys do this on Memorial Day on rocks as opposed to a thrown chain:

guy on 426: JB welded, hasn't leaked since

guy on XR250: bought brand new WR450, hasn't leaked since :thumbsup:

  • yzrider6857

Posted July 20, 2006 - 04:22 PM


I wouldn't mess around,buy a new case.The case is cheaper than a new motor. :thumbsup:

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