The serial number posted, appears to be a Mercury number. In order to answer your question, the horsepower of the engine is needed also.
my serial # is 81885 on a Silverline boat.
How old is my Kiekhaefer Mercury 7.5 boat motor Serial number 3374590
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.
7o
1977
1070310
1986
1981
its a 1956
More information is needed to answer this question. For most outboards, the brand, model number, and serial number is needed.
2k210405
The year model for a Johnson outboard is determined from the engine model number, rather than the serial number.