Probably 50:1 which is 0.2 litres/10 litres. Use TCW3 rated outboard oil. Some engines were originally 100:1 to reduce emissions but it turned out to be not so good for the engine life and most people now use 50:1.
Originally a 1985 Johnson would have been 100:1 but within a couple of years or so they realised this was a mistake after large numbers of warranty claims and all were changed to 50:1.
100:1 decals should have been removed and owners manuals amended.