Ok, this is my first post here. I'm looking for some opinions on an engine problem. I have a Kohler command 20 hp in a 310. It was changed out from the original 15 hp unit. The engine starts, and runs well, has plenty of power and doesn't smoke. The issue is that there is engine oil coming up the breather tube and dripping into the air cleaner area. From what I understand, positive pressure in the crankcase can only be caused by a few things...but.... it can't be good. So, plugged breather filter, rings, ?? Any insight is appreciated.