Re: fuel/oil mixture on a 1985 7.5 evinrude
50:1 using a TCW3 2 stroke outboard engine oil
That's 20ml per litre
or 1 pint in 6gallons approx (US pints and US gallons or Imperial pints and Imperial gallons)
or 2.56 fluid ozs in a US gallon
or 3.2 fluid ozs per Imperial (UK) gallon
and it is 50:1 even if you find anything that suggests 100:1