Is this heat crack's or casting mark's

[CalsXS2]

The first 2 pic's are of the major crack around the rear motor mount. I had it welded from the topside when I first got the bike. It didn't look as bad as it does from the inside. I was cleaning everything up getting ready to weld the crack, and then I noticed all the other crack's. I have old eye's. They look like crack's to me. My buddy says they're casting mark's. But he's only a couple of year's younger than me. So his eyesight isn't much better.

So is this case junk. Does it look like crack's to you guy's. Should I just run it. Or do I need a new motor. I have this tore apart for a rebuild. Unfortunately, I all ready bought the NOS rod's and they won't give me my money back. Maybe if I showed the owner my junk he would feel sorry for me and give me a refund. If not, I'm out $200 If this case is junk. Thanks.

 

[scabber]

Looks like good old yamaha casting marks. If it's not there are around 100,000 other junk cases out there. If it dont leak oil dont fix. If it does JB weld. Just my opinion

 

[CalsXS2]

Well, the motor mount crack was leaking for sure. But it's getting welded as long as the rest will pass. The rest of the motor was dry except for a leaking seal.

 

[kopcicle]

the obvious crack in the first pic looks like it was caused from one of two possible problems . I've seen debris carried up by the gear box and trapped between the case and gears break that area . The other was loose motor mounts .

The rest is just casting marks .

~kop