Re: Wards Sea King, repair manual, Identify year
OK, the 28925 fits with an Eska-made 5hp model from 1969. It's air-cooled, with an impeller pumping water to cool just the exhaust.
You would use 2-cycle oil in that one, the type made for chainsaws, etc, and should mix it at 16:1, I believe. It could be a leaner mix than that, but I can't say for sure, and you'll be safe with that mix.
The model number would actually be CED-28925, rather than what you gave, but the numbers match, and the cowling looks about right for the year.
You can confirm this by pulling off the cover. You should see fins on the single cylinder engine.
A lot of parts are still available for that outboard from certifiedpartscorp.com, but you won't see them listed on the site. You have to call the number on the site and talk to someone.