Hi guys, I have an Evinrude, 1962 40 H.P motor. Model # is: 35933L. In my repair manual, (Seloc) it tells me to use a 24:1 fuel/oil ratiofor this model, yet on a different page, it says to use a 50:1 ratio but there is no model number listed, just the horse power (40) and year (1962)...