on my old mariner motor(40 hp 1989 japanese) I bought a gear oil pump that had a fitting for yamaha outboards in it--I figure that the drain in this motor was the same as a yamaha but I was sadly mistaken--the oil level hole at top accepted this fitting(8mm I believe) perfectly but the bottom drain/fill hole was much smaller--like 4mm or something---can somebody fill me in(no pun intended)

