If it is a 2 cycle where you mix the oil with the gasoline then use 2 cycle marine oil. If it is a 4 cycle then use the weight recommended by Evinrude.
it is a 1977 motor
The boat motor.
1992 E30RENR 1992 Evinrude / Johnson Evinrude
1980
its a 1966
1978
1975
50:1
.030
"CT"=1983, "A"=Revision
1949
1986