On my 1995 XR250R, I have a crack by the oil filter cover but
not the cover, it is on the whole big cover, which I think might
be really bad. Will I have to replace the whole cover, is there
anyway to seal it? I guess this will cost a fortune if I have
to replace it. As soon as I start riding the oil starts seeping
out this little tiny hairline crack. Thanks, Nancy (AKA Harleygal):think
Depending in the material you should be able to get it welded-ask your shop about that. Otherwise, I sealed a big, leaking crack in my Husky's side-case with epoxy that held up for over a year (finally sold the bike that way).
If its not a big crack or anything I say touch it up with some JB-Weld. Me and a few buddies repaired leaking crankcases before with it and they don't leak anymore. Good luck.....:)
I cracked a side cover on my XR400 and sealed it with JB Weld. Lean the bike over before (to keep oil away) and use acetone to clean the area. Also, let it cure per the instructions. Should work.
Is that cover magnesium? If so it should by law say it is. If so welding is out of the question I belive. If you use the JB weld, get it good and clean like they said and wire brush off any paint or finish. I wold recomend a slight V out with a file for better surface area. If its magnesium be carful, the stuff kinda can explode if you try to weld or smack it to hard. Thats why they have to label it I think.
Most magnesium alloys can be welded, brazed, and soldered. There are some magnesium alloys that cannot be welded successfully with standard methods. I don't think it is likely to explode or burn, unless you grind it into a pile of dust and then ignite it.
As to the original post: If you don't want to split the cases to have it repaired or replaced, and don't mind the look of J-B Weld, it may do the trick - as many have said above. I used it on an old Honda I used to have after the chain broke and was driven through the crankcase, and it was still not leaking when I last saw the bike some years later. I think it depends on the location of the crack, the thickness of the material there, and whether it is prone to flexing or vibration. Good luck!
since it's near the filter, have you pulled out the filter to see if you can get at it from the inside? if so, do it that way, just make sure to watch for any oil passages, and keep the area around the filter open (so oil can flow).