Almost ready to see if the old B I bought will start up. I took the air cleaner off and washed everything with kerosene and put it back together. Question - where and how much oil do I put in the cup? I don't see a fill line, everything is pretty dirty. Does the oil go in the center or in the ring around the outside? I am guessing in the outside ring, and just below the small holes in the center cup. But thought I would ask someone who knows for sure.