Dale H is correct, as always.
When I have to find out something (almost anything)....I just type
... spark plug gap 1977 johnson outboard 25 hp ...
into the search line on Google. Google then finds some page or list where my answer is.
try ..... weight of a gallon water ..... or ....... height of the rocky mountains ..... or almost anything at all.
Do not ask...... what do women really want ... Ha Ha ( I tried that one, and there really is a bunch of answers... Who knew??? Ha Ha
regards, richg99