Have a Zee2, second owner, I went to change the oil and it appears that the previous owner(passed Away) messed up what appears have been a plastic nut or something to open a valve to let oil out. What was supposed to be there and I assume it turns counter clockwise to open and clockwise to close, what I see is a nub of whats left, pretty sure this is why the oil is so dirty because he messed it up and could not drain either, What I can tell you is it look like there is a Tee and when the valve is open the oil comes out the fisrt down port of the tee. Thanks and I hope I explained enough for someone to help me.