Mike,
Congrats on your garage sale treasure. My cheapest outboard and first Wizard cost me $15 at a flea market. I only got it for that because it was missing the propeller,prop shaft,lower gears, and gear case cover.
Your Model number indicates that your corsair motor was made in 1950 and is a 2 cylinder 5 hp motor.
Corsair was made by Scott-Atwater and was discontinued in 1957 after Scott was sold to McCulloch.
It is a good bet that the 5 hp Scott-Atwater motor produced about the same time has parts and functions similar to your corsair with only the cowlings being different.
I found the specs for the Corsair 5027 in a chart:
The original spark plug was a Champion H10J
Spark plug gap .035
point gap .020
original fuel mix 8oz oil per gallon or 16:1 ratio.
Use Lubriplate 105 motor assembly grease available from NAPA in the lower unit.
I suspect your carb needs cleaning and your float might be stuck open. varnish in the carb can be cleaned using a bottle of methanol fuel treatment or denatured alcohol.