I bought an old Boston Whaler with (I was told) a 1984 55HP Evinrude. Howver the model number on the transom mount (55EL77D) tells me it's a 1977 Johnson. The motor is all Evinrude, paint, cover, etc. I've taken it to an OMC dealer but he couldn't confirm what it is. I can't find a Welch...