1981 merc 200 performance

[jamesbalog]

so ive had the boat in with this motor for about a month now and wanted to share what i was getting numbers wise. I was expecting a little bit of a jump from my johnson 175 but i do not see it. are my numbers normal or what could i do to improve them?

The boat is a 1990 center console 20 sport. The boat has bottom paint. It is ran pretty heavy usually with 45 gallons or so of fuel, a kicker motor, 2-3 200+ pound adults, one 150qt cooler with ice and fish and more rods and tackle than i care to talk about.

im running a 3 blade 14.25x19 aluminum prop

im maxing our at around 42mph gps speed at 5100 rpms trimmed out

getting around 36 mph at 4500

30mph at 3900

26-27mph at 3500

im getting pretty much the exact same numbers as the johnson 175 i had. Im not sure about fuel burn as i pre mix now and have never filled the tank to 100%capacity. It sure seems like im burning less fuel now although its just a guess.

i was expecting more but im not getting it, anything prop wise i could do to improve it?