here are some more pictures I uploaded for Charlie:
Well, I am confused, as usual…This engine seems to use a combination of the oring around the upper bearing and the vacuum drain systems…
My question is: does that vacuum groove in the crankcase go into the oring groove? Kinda hard to tell by the pictures. If so, this seems like an engineering "mistake". The dark wet surface on the crankcase shows pretty clearly where the leak is, sure does not appear to be a crankcase sealing problem. I will have to look closer at the pictures…