I have a 1950 Evinrude 7.5 Hp outboard (4434-12039), Its recomended (on the fuel cover of the motor) a 16/1 ratio of a high grade oil of SAE 30 or 40 body, such as Mobiloil outboard or comparable straight mineral oil. Do I really need to use such a rich mix of oil if I the current brands of...
