I need some help. I have a 2003 250 h.p. yamaha 2-stroke. It has the pointed nose cone. I used to change the oil in my lower unit in my Mercury but have always had it done on my yamaha. So I went in today and got the oil,l went to the back of the boat and noticed there is no lower plug. My water intake is there where I expected to find the lower plug. If you look inside the screening you can see an allan head. Is that the lower plug to drain the oil or will that get me into the plug? If not does anyone know how and can you advise me?