Re: How do I identify a 1958 Evinrude Big Twin 35?
A less reliable, but sufficient indicator for most people, is paint color. The '58 Bigtwins have both light blue and dark blue paint on the hood. The middle portion, where the "Evinrude" decal and emblem are located, is white. The rest of the motor will be dark blue.
There were also '58 models (as well as other years) that were painted gray. Those were the "Lark" models, sometimes also called "Deluxe" models. The motors may have chrome trim on them and a cover on the face of the motor, which must be opned to get at the mixture knobs.
The 1957 model has black paint where the light blue paint is on the '58. On the 1956, the center section of the hood is black and the portion above that is white, as viewed from the side. I believe that the '56 is also 30hp, not 35hp.
Starting in 1959, the ERude 35hp motors went to the "fat midsection," which in the Johnson version, was referred to as "Super Seahorse." The term "Superquiet" was also used, but I can't remember if it referred to one or the other, or both.
There is also a difference in the shape of the mixture knobs on a 1958 Bigtwin, as compared to the older motors. The '58 has knobs with a concave face, while the others have a flat face.
One aspect of the older motors, however, is that many of them are "parts queens," meaning that parts from various motors of various years, have been used to keep them going. Powerhead preplacements off of another motor are very common and may be from either a Johnson or Evinrude motor.
Ultimately, however, the data plate located on the front of the swivel bracket (see F R's diagram), is the best source. If you have the proper information (which most people don't), you can determine year by the serial number on the Welch Plug, but that will tell you nothing more than the year of the powerhead, even if you are able to do a cross reference.
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