Circumstances may dictate what type of outboard you have. An older planing boat would have its max power stated, but for a 2 stroke. Chuck the added weight for same hp 4 stroke on the back and it nearly sinks the boat.
From around 50 hp the 4 stroke makes sense due to the much better fuel economy and a much quite engine.
Smaller engines are not so bad on fuel as 2 strokes.
The 200hp I had could easily empty a 25l tank of fuel in 5 mins. It was 5 mins of 70 + sheer terror, mind bending acceleration ,but great fun.
I think what would be an interesting exercise - to find out how many people have gone to lengths to source 2 str rather than 4str.
How many have decided they would buy a 2nd hand 2str instead of a new 4str ... given that a few years ago - that same person may have bought new 2 str.