Two things are needed to determine the age of a Mercury outboard, the serial number, and the horsepower rating.
In order to determine the age of a Mercury outboard, in addition to the the serial number, the horsepower is needed.
11.92
Mercury outboard, 8hp, sn A721731 manufactured in 1987.
A 90hp Mercury outboard, serial number 6114748 is a 1982 year model.
There are two items needed to determine the age of a Mercury outboard, the serial number, and the horsepower rating.
Your 4 hp Mercury outboard, serial number 2779869 is a 1970 year model.
A 65 hp Mercury outboard, serial number 4574019, is a 1976 year model.
A 25hp Mercury outboard, serial number OG027076 is a 1994 year model.
An 8 hp Mercury, serial number B387142, is a 1989 year model outboard.
A 25 hp Mercury outboard, serial number 6370735, would be a 1983 year model.
A 90 hp Mercury outboard, serial number OD067645, would be a 1991 year model.