1985 75hp Mercury 4cyl carb upgrade: achieving 85hp possible?

[creol]

I have thought about upgrading my brown-band 75hp outboard to 85hp by swapping carbs with an old blue-band 850 Mercury. My outboard is Belgium made, serial no. 9403250.
Is this the way to achieve 85hp, or are there more factors limiting potential horsepower than carb size (exhaust/intake port size or something) or I'm a completely wrong? A few wise words from a Mercury specialist are needed. Thank you in advance.

 

[DirtyOldBoat]

Re: 1985 75hp Mercury 4cyl carb upgrade: achieving 85hp possible?

I don't know about that particular motor, but on the inline 6s, which are basically the same, the internal porting is different and there is no way to change it.