I recently bought a 550 and noticed that oil is leaking out 2 of the bottom holes behind the plate where the external valve would go. Nothing is coming out of the top one. When I checked my uncles super 55, there was a bolt in the bottom rear hole and the other 2 holes had pipe threads with a plug in them. He has the same cover plate as I do. Are these suppose to be plugged lie the super 55? Thanks for any help.