The same powerhead is used on the Evinrude Sportsman built from 1948 through 1951 – One of the best singles ever built (in my opinion.) The Tilitson carburetor is different as the bypass tube going down through the center of the Venturi picks up a set amount of fuel from the high speed jet. The idle adjustment needle valve adjusts the amount of air that is mixed with it. That tube is easily narrowed by stale oil. Be sure it is clean or it will run lean at an idle and sneeze a lot.
gary-in-tampa—–do you have the drawing for the lower unit showing the parts including gears & gasket. Also what is the oil or grease used in lower unit?