2004 yz 250f

My chain broke and busted a hold in the side case. The hole is just above the front sprocket and is about 10 mm in diameter. Can this be welded? Has this happened to anyone and how did you fix it? I have a picture but cannot figure out how to attach. How do you attach a picture?




Since there is no pressure fed oil there, you probably could patch it with some JB Weld or some other equal. You may have to put a piece of masking tape over the hole to keep the "putty" from oozing into the case. If so, you'll have to cover area past the hole around the perimeter. Rough it up with some sand paper or steel wool. Then wipe it down with some brake clean to insure good adhesion.

If you do decide to patch the hole, I would ride it around easy for a bit with an occasional stop and look.

Ultimately you may want to weld (tig) the area or replace the case.

Where did that piece of case go?

Where did that piece of case go?

I'd definitely have a close look around the inside of the motor to ensure no large chunks are lurking just waiting to destroy everything!

Thanks for the input. I've talked with someone I work with and he tells me he can weld it but the case needs to be split, steam cleaned for a good weld. I'm thinking if I go that direction I just as well buy a new left side case. Any thoughts?

I honestly don't think anything went inside.

Buying a whole new case half would be the correct repair. Welding it up is #2 and JB weld is an option my cheap broke ass would do. Maybe even use a penny to cover the hole.

Loctite do a great aluminium filled epoxy filler, I have used it several times and found it longer lasting than JB weld. make sure the case is really clean, contact cleaner or alcohol, I like to warm the cases up with a fan heater till you can only just put your hand on it, seems to open the ally up and gets a better bond. For large holes if form am little patch with some ally sheet and epoxy this in place. I have had this area welded on my old XT400 and always had trouble with the drive shaft bearing feeling notchy and wearing quickly because the casing was pulled out of round with the heat of welding. A kew case would be the best way but I would go with epoxy till you are due to pull the motor down.

Thanks Guys. I don't like the idea of half doing anything either Swede73, I will just suck it up and buy the new half case.

Do any of you know if a 2003 left case and 2004 are the same? I've found a 2003 and 2005 on ebay.

I think they are the same. Find a website that has the parts fiche and cross reference the two years part numbers

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