Re: evinrude identification
The J in the serial number means it was assembled at the Johnson plant in Waukegan IL. That means very little from a practical standpoint because a lot of Johnsons were also made at the Evinrude plant in Milwaukee. AND both were also made all over the world.
BTW, Johnson did not "take over Evinrude". If anything it was the other way around when back around 1936 Ole Evinrude's Elto and Evinrude and Lockwood, collectivly called Outboard Motors Corporation acquired Johnson and formed OMC --Outboard Marine Corporation.