had a enya it was cacked all the way to a opening cant remember if it was ft. or back looked like yours i had it tig welded
it ran about 1 tank of fuel and broke right through the weld i jb welded it and the same thing happen on the other hand i got a enya that had a small hole driller through the crank case and that held wt. jb i think most of the eng. are some kind of pot metal alum. it cant hurt to try wouldent spend much haveing it welded if the jb dont hold thats what happen to me if you could find a used crankcase adios jack