Can two 90hp outboards(2 stroke) on a 30' vessel be replaced by a single 140hp 4stroke and a 15hp standby .

Question

Current cruising speed 20 knots and top speed 28 knots.Never cruise the open seas.Prefer calmer waters and lakes.Good or bad idea?New at this and have everything to learn.

Answer 1

Seems a little underpowered> the 140 will work itself quite hard> the 15 will do nothing but make smoke won't move the boat straight or in the currant or wind>

Answer 2

I see no reason why not

Answer 3

It really depends what kind of boat it is and how much it weighs.  But I guess since you can hit 28 with the two of them - I would guess that a single engine with the same power would be fine. And since you are not going out in open water - you don't need the peace of mind of having 2 motors... I would look more at the 150hp yamaha and up though