Modern Vespa

I am curious if this hole is supposed to be here...? It goes all the way into the bearing, and I'm thinking this could be why my engine was leaking everywhere....? (The oil seals all looked fine.) I can't find any diagrams of this to know whether this hole is supposed to be here or if this case is damaged....? I'm new at this stuff. Also, what kind of cleaner should I use to clean all of this gunk off with that is safe?

Yes it is. The fuel mixture comes in to the crankcase, runs down throught the hole and lubricates the bearing.

Oh thank God! What should I clean all of this crap off with? And is it safe to scrub hard? I've tried degreaser (Purple Stuff) and this gunk is too stubborn!

When It's really bad, I use a petrol based engine/parts cleaner and some small wire brushes. Much easier to do when you have the engine out of the bike.

After I've got it back in there if it starts to get too grimy, I'll just spray some Simple Green Pro HD(the purple kind) The green kind is not supposed to be good for use on aluminum.

But usually I just leave it oily until the next time I drop it.