My year 2000 carbed Mercury 4st. 90 hp specifications seem identical to the 75 hp version. Presumably the extra power is found by pouring more fuel into the engine? (bigger jets?) My usual cruising revs are between 3000 and 3500. - around 21-23 knots. WOT is just short of 40knots and the fuel vanishes in minutes
. I rarely want to go that fast and can't afford it anyway.
Just wondered if I could 'detune' the engine to the 75 hp spec., would I get better fuel consumption at my 23 knots? Presumably, with less power one would need more revs to keep the speed.
I just wondered if the engine would be more efficient running at higher revs and therefore burn less than it does at the moment at my cruising revs.
Mind you, there's going to be more stress at higher revs. Mmm! Perhaps I've answered my own question?
Any experts? Any thoughts?