a crankcase leak is a major biggie. It can make your motor nearly impossible to start and cause it to burn up from too lean, when you do get it running.
Pics would really help!
I suggested a dab of JBWeld as a temp fix to see if everything else is ok and it's gonna run. a smear of JBWeld ain't gonna hurt nothing! and it may plug the hole for a bit.
If there is a case mismatch, or defunct gasket problem, the only permanent fix will be a complete teardown. Is W prepared for such a task?
I'll admit again, I'm a real hack!
Smear a blob of JBWeld on it and see if you can get some miles out of it!
and I'd just as soon buy a complete lower end, or even another complete motor and go through the Alf proceedure for new chinagirl engines while riding around a bit on one that could very possibly expire. At the bottom of the barrel it is never a bad idea to have back-ups ! :-)
My goal is cheap, reliable, personal transport, below the tax collector radar. Fun counts for a lot!