Weight is the biggest issue for me.
This rules out 4strokes although I can
clearly see the advantages of them.
3.5hp tohatsu rebadged as mercury
Is the best power to weight at 13kg.
As soon as you go above this the weight
Is up to 17-20 kg
If you go to a 6-8-9.8hp the power head
Is the same weight at 26kg
So for me the answer is mercury
In two stroke.
This has been able to plane my dinks with 1 person.
Now have a 10' portabote & think that this will
Plane with 2 on board.
Why the merc over the tohatsu ?
The ancillaries are better quality..
In this size engine fuel
use is not really an issue.