90's Evinrude 15hp

[Curapa]

I just picked up a small boat with what I believe is a 90's Evinrude 15. I am trying to troubleshoot what I believe are minor problems.

First, does anyone know how to wire the starter for a key or pushbutton? There are only two wires coming from the motor, a ground and positive. The people that I bought it from always pull started it. I am assuming I am overlooking something.

I am trying to upload a pic from my phone but the images are to large. I will have to resize and upload later.