Hole with a crack in my engine :/

[jthompson9134]

So, I have a small hole in the crank case of my XV750. There's a hairline crack working its way up, which is concerning. Fortunately, there is no real oil pressure at this point so it was never spewing oil (although it definitely dribbles a little out when running), and I've heard JB Weld should do the trick. Question is, should I grind into the crack a little bit to have a good seal with the JB weld? I've considered drilling a small hole at the end of the crack to prevent further spreading, but I just want to find the best way to seal this hole and be done with it. Any suggestions on how to approach this?

 

[irk miller]

As many cases as I've seen repaired by JB Weld, I'll admit it works to a degree. But the proper way to fix it would be to weld it. JB Weld would be the thing to do to get you some miles before you have to get serious with the repair. Looks like you might be able to fix it without pulling it apart, regardless. Drilling a very small hole at the end of that crack is definitely the thing to do to prevent the crack from spreading, but you may get more leakage.

 

[SONICJK]

If you're just looking to fix it now JB will be fine.
Drill a small hole at the end of the crack 1/16" or so, then grind a small V into the crack area with a dremel or similar. Clean it off with acetone and pack it full of JB.

My only concern would be the threads on that bolt appear to be visible there, you wouldn't want to JB the bolt in permanently. Pull the bolt out and clean it up, then reinsert it and very carefully with a small paint brush put vaseline on the threads without getting any on the case. That should keep it from sticking to the bolt.
JB weld is amazing stuff.

Or pull it off, clean it up and tig it

 

[Hurco550]

I tig weld often, and have one at home. Even so, I've definitely JB Welded a fair share of case covers. IMHO, its always a crap shoot what the aluminum is going to weld like, even when you think its clean. Sometimes its fine, and sometimes its like welding oil filled swiss cheese.

 

[SONICJK]

I tig weld often, and have one at home. Even so, I've definitely JB Welded a fair share of case covers. IMHO, its always a crap shoot what the aluminum is going to weld like, even when you think its clean. Sometimes its fine, and sometimes its like welding oil filled swiss cheese.

100% agree.
I think I'd JB that if it were mine. then paint over it black and no one would ever know.

 

[cxman]

put the right bolt back in to that looks like it was caused by the bolt busting the case out from over length

and the pushing also caused the crack from stress

 

[ridesolo]

I think I'd JB that if it were mine. then paint over it black and no one would ever know.

Hmmm, next time you've got a bike for sale I'll remember that!

 

[Out]

Is that right at the front L where the starter drive is? That always seemed like a high stress point from an engineering standpoint, or mis-engineering stand if you are one of the many with the "box of rocks" starter issues. That looks like a tough spot to repair. Not impossible, so think positive. I would say JB is temporary at best. If things do not go well I am sure I have a 81-83 XV 750 engine.

 

[ridesolo]

put the right bolt back in to that looks like it was caused by the bolt busting the case out from over length and the pushing also caused the crack from stress

Good point. Perhaps when you have the crack and hole repaired you could replace the original bolt w/ one that's a bit shorter. That could eliminate some pressure on the crack by eliminating the potential over length.

 

[irk miller]

Those bolts aren't too long. As Snout recognizes, that is a starter mounting bolt. The hole is drilled through from the cover to the starter.

 

[SONICJK]

Hmmm, next time you've got a bike for sale I'll remember that!

I'll tell ya what I JB'd. I just may not take credit for it lol.
"clutch is a little sticky, theres an oil drip over there, and some idiot JB welded the case right here, but it seems to be holding nicely" LOL

 

[ridesolo]

I'll tell ya what I JB'd. I just may not take credit for it lol.
"clutch is a little sticky, theres an oil drip over there, and dome idion JB welded the case right here, but it seems to be holding nicely" LOL

Ha! The dreaded PO! You can't help but wonder how many innocent Previous Owners have been blamed for things. After all, the term "Innocent Previous Owner (PO)" is surely an oxymoron, right?