Evinrude outboard engines rely on the model number for positive identification, and the number is located on the identification plate near the engine transom mount. Model identification codes vary depending on the year of manufacture, but the system is easily translated.
1980 and Later
Most 1980 and later models will have the year of manufacture stamped on the identification plate. For those that don't, the following method is suggested: the model number E225TXEUD translates as "E" for Evinrude, 225 for the horsepower, and the second and third to last letters, "EU," represent the year. In this case, 1997. Evinrude's system for decoding the year of manufacture is: I=1, N=2, T=3, R=4, O=5, D=6, U=7, C=8, E=9 and S=0.
Pre-1980 Evinrudes have a shorter model number and different numbering system; however, the numbers are in the same location. Model number 85990R translates as 85 horsepower and "9" represents the year of the decade manufactured, in this case 1979. This code neglects to designate the decade, so a bit of guessing is necessary; a 1969 model will look different than one from 1979.
1950 to 1969 Evinrudes follow the same basic system as the pre-1980 models. The model consists of five numbers; the first two represent the horsepower and the third number is the year of the decade manufactured. As the number omits the decade, It may be harder to differentiate a 1961 outboard from a 1951; consult a model number list for reference, such as the one available at the Parts Warehouse website (see References).