sometimes on the engine block there is a silver colored aluminum plug with a serial number stamped into it. You could call Evinrude customer service with that number.
Yes I believe they're called "welsh" plugs & sometimes they are rubber coated. The plug should be stamped with the model# above the serial#.
Model# is what tells you the year. INTRODUCES is the code OMC used. I = 1, S = 0 and so on. The second & third letters from last reveal the year. For example my motor's model is E90TLCDC. Which means it is CD or '86.
