I have my CR250 from 2001. It somehow got itself a crack on the case. The crack starts on the very thin face that mates with the stator cover and goes back half an inch. The aluminum is about 1/8th inch thick there or less, and it's a small crack right on the top center of where the stator cover meets the case.

JB Weld? Real welding? New case?

Srinath I know you know what I need.

The only real fix is a new case.  Seond best is to have a shop weld it but it won't last long.

Ghetto, but effective, would be to drill a 1/8" holes at the end of the crack...this will prevent it from spreading...then using a hard epoxy like JBWeld or ProPoxy to seal the crack.

Is there any performance lost because of this? It doesn't feel like it. I don't think the stator side is pressurized.

My 86 LT250R has a cracked case.. I JB Welded it over 3 years ago.. Still runs like a bat out of hell, and no leaks  

I think that my LT is made mostly of JB weld by now  

Great, this is what I like to hear.

I was planning on picking up a trials bike this summer, but it's nice to have two offroad bikes for two different purposes. 

I'll try to find a case, but JB weld it is for the time being.

only time you'll lose performance is if there's a significant vac leak from the case.

jb weld is your friend. i welded a nice crack/hole in my tank and its held up just fine for almost 2 years!

I JB'ed a fin back onto a cylinder head and my radiator on my Honda.

Jake

It's a matter of: cost of case < cost of engine.

You can JB weld it, it's been done before, no biggie...just keep a very close eye on it. But if it goes, you can probably kiss your engine goodbye.

And a crack in that spot (if I am reading your description correctly) is caused by running the chain much too tight.

Devcon is better than JB Weld...

I will weld it ... not JB weld it. I did on the sausage I am working on.
Cool.
Srinath.