Originally Posted by Englishman
Yeah, there's not supposed to be a seal there. The engine breaths into the primary and into the atmosphere via the tube that attaches to the top of the inner primary (which in this case is part of the cases). The three little holes between the pulleys are what is supposed to control the oil level in the primary.
If you put a seal on the crank, you'll blow every other gasket in the engine, don't ask me how I know
Thanks man that was a nice description