Evinrude and Johnson outboards prior to 1965, require a 24:1 ratio, so the 64 model would be a 24:1 fuel to 2 cycle oil mix.
1959 thru 1963 Johnson and Evinrude use a 24 to 1 ratio. 1964 and up is 50 to 1
Mercury outboards prior to 1966 use a 24:1 fuel to oil ratio.
The Evinrude outboard, model MQ-10R, would be a 1964 model, 9.5 hp.
5.5 HP 1964 Evinrude Fisherman 5402B-E02180
Hi there this outboard was made in 1964 hope that helps you
1964 90-S Starflite
Before 1980, you use the first four numbers of the Evinrude boat motor serial number to determine the year it was made. Motor serial numbers beginning with 5402 were made in 1964.
1964 or 1965
24-1 until 1964, then 50-1
try iboats.com
The later 7 hp used 24 to 1.
50 TO 1