Re: 2004 115hp Mercury
If you look at the side of the engine cover it will say EFI Four-Stroke if its a four stroke. If you still don't know, lift the engine cover. A two-stroke will have a large oil resevoir on the side. The numbers ELPTO are Electric Start, Long Shaft, Power Trim and Oil Injected. Oil Injected is the key here. Four strokes are not oil injected.