I figured as much. We have a friend who repowered a 30' 1991 Suntracker
Party Hut pontoon boat this spring. This thing had a 75 hp 3 cylinder
Mercury 2 stroke of the same vintage, it moved OK, but not great. He
wants to sell me the 75hp for $1200, but it is too loud for me.
Now it has a 115hp 4 cylinder 4 stroke Mercury. (My friend says 2004 is
the last year for his Party Hut... next year he'll get a 32' Party
Cruiser, which weighs about 1000 lbs more and needs the 115hp.)
My friend says with the new motor they can go much faster, if they
choose, it burns about the same amount of fuel, and now you don't have
to shout to hear each other when the motor is running. I rode with them
a few times last year. What a racket from that motor... If the 40 hp 2
stroke is half as loud, I'd still hate it, because I'll be sitting right
next to it. At least on the Party Hut you could get some distance from
the motor.
I think the 115 hp is the maximum for his boat.
My boat is now at the dealer. They are going to put the motor on
tomorrow. I'm going to take it for a little run after work. If the price
is right, maybe I'll take the 2 stroke and use it for a year or two. I
believe it is sort of a waste of money, but then again I'm cheap.

Tony Thomas wrote:

Actually it will perform better than the 4 stroke since it is lighter and
has better acceleration. As said before, I don't believe you will be happy
w/ a 40. You never want to run the engine at wide open for long periods of
time. Poor fuel economy and very hard on the engine.