This motor is my 1968 Evinrude 3hp Folder. It has a coupler that has a rim and a washer to maintain its position on the lower portion of the drive shaft assembly just like the 1967 Johnson 3hp Folder.
So, it looks like the 1965 and 1966 Folders have the couplers with the stainless steel retention clip and the 1967 and 1968 have the coupler with the rim and the washer. I would assume the 1969 4hp Folder would have the same set up as the 1968 3hp Folder.
