maybe SR in model number=2004y
iBoats has a page for identifying engine model numbers...follow the link below - it leads me to believe it is a commercial johnson engine, 14 HP, from 1985
http://www.iboats.com/basics/johnson-evinrude-commercial.html
i think on those 15 hp motors (like on my 6 and 8 hp rudes) the starter has to be moved out of the way to access one of the nuts.