Crankcase Pressure

[Memphisspider]

76" spider 1800
How much crankcase venting is too much through the breather pipe?
I am getting oily splatters in the carb breather visibly spotting the foam filter element.

[Fi8spider]

Inside the actual breather pipe from the block to the air filter there should be a brass spiral brush looking thing called a flame arrester, check to see if you have that in place.
Cheers