Crack in engine case??!!

[ericmu17]

I saw this crack today and freaked out being that I had just had this motor rebuilt. I googled XS650 engine crack and this came up.

http://www.xs650.com/forum/showthread.php?t=10431

How common are these cracks? Does anyone else have them?

 

[jd750ace]

If it don't leak oil it's just a casting flaw. Very commonly seen on these cases.

 

[jayel]

looks more like a crack from over tighten head/cylinder stud to me, but like Ace said if it don't leak don't be to concerned... try scratching acrossed it to tell if it's a casting flaw or not, a casting flaw will have metal under what you see on the surface, a crack will not

 

[gggGary]

I'll vote casting flaw. They happen when the aluminum cools a bit quickly and shrinks away from the mold. That's a popular location for them too. It varies engine by engine, some look like Shelob's been casting webs others are completely smooth. It's appearance only.

 

[Uncle Bryan]

This scared the bejesus out of me till I realized that it was just casting flaws (slag).

Clean it up and keep an eye on it and see if it 'sweats out' any more oil