You forgot to divide by the gear ratio. With a 1.87 gear and taking into
account an efficiency of 90% for a SS prop you get 2.2 MPH. But increasing
from 190 to 205 hp is probably not enough to increase by 2" of pitch on top
end. You could go 1" of pitch and get 1.1 MPH or the extra rpms w/ the same
pitch will give you the same.

Again - your comparing a 1500% increase to an increase of 8%. Don't come
close to being the same.

--
Tony
my boats and cars at http://t.thomas.home.mchsi.com

-
"Paul" wrote in message
ups.com...
But with that increase in HP you should be able to run a higher pitch
prop. A 2" pitch increase at a prop speed of 2500 rpms should give you
4.7 MPH speed increase. My 9.8 would never be able to get to WOT with a
13" prop on my boat. But the 25 HP has no problem. If you do get more
ponies from an engine upgrade. You should look at changing the prop. A
prop turning at a certain speed is only going to go so fast not matter
how much horse power is behind it.

Paul