Sorry Yes it is a Sea Horse,Oil mixture is like its supose to be,Whats the impeller?Sea King is not a Johnson, reneage. Did you mean Sea Horse?? Johnsons were Sea Horses for many years.
CD-17 is a 1960 Johnson 5.5.
Sounds like you may have forgotten the oil in the fuel or to replace the impeller.
Give us more info, please.