Ole Evinrude patented his first outboard motor in 1911. Between 1915 and 1928, a variety of models were produced. After the tumultuous merger of Evinrude's first company and competitors like Johnson Motors building boat motors under the same name, model numbers based on motor horsepower began to appear. Unfortunately, the model numbers were not consistent. Only after 1980 did Evinrude standardise their model numbering system, which can help an owner to find the year of an Evinrude outboard motor.
Search for the Evinrude nameplate on the motor or on the motor's mounting bracket. The model number includes the information to help you find the year that your motor was built.
Look at the second letter of the model number; it will be a "J," "E," a blank space or a "V." The letter "E" in the second position of the model number confirms that the motor is made by Evinrude rather than by Johnson (made by the same company, indicated by a "J").
Record the model number -- you may need it for another purpose at some later time. Note the last three letters in the model number: the last letter is a model run designation, added to the model number as a suffix.
Decipher the code formed by the two letters to the left of the model run designation. These letters form a simple substitution cipher, where a letter in a key word represents a number. With modern Evinrude motors, the key word is "introduces"
Substitute the number 1 for the "i" in introduces, 2 for the letter"n," 3 for the letter "t," 4 for the letter "r," 5 for the letter "o," 6 for the letter "d," 7 for the letter "u," 8 for the letter "c," 9 for the letter "e" and 0 for the letter "s." If the model number of your motor ends with ED A, disregard the A. Substitute a "9" for the E and "6 "for the D and you discover that your motor was made in "96," or 1996.
Further information on pre-1980 Evinrude model numbers can be found at Master Engine. Other organisations, like the Antique Outboard Motor Club provide ideas and information on restoring older Evinrude motors.