after reading i do not think you would hit 35 mph dguidry, sorry buddy, if that was the case i will TRADE my 35 horse right now for a 23.....anyways i read you are still running your stock muffler, whenever i modded my motor they guy that did the work told me to put on a performance exhaust asap b/c it flows better and keeps the valves cool. i planned to leave the stock one on for a while but he said i would burn a valve, im not sure how accurate that is maybe one of these mechanics savvy guys can chime in on it, but its something you might want to do right away b/f putting too many hours on your mods.

Coefficient of slip as in "prop slip"!! Sorry misunderstood the posts on this. Don't know much about this. How does the coefficient change with increased rpm over fixed throttle range?

Here is a site with calculator that caculates slip coefficient. It's a functioned pitch, speed, rpm and gear ratio:

Yesterday tested my boat with following load 24.8 mph at 3300 rpms

Conditions: ripples and mild wind

Me 258 lbs
Trolling motor
48 ice chest with 10lbs ice 3lbs beverages
6 gal fuel
2 batteries
Tool box 5lbs
Cabella chair pod
Tackle box

If u input the numbers dguidry posted about speed into the prop calculator, you actually get a -30 percent slip. This is with 27mph at 2500rpms. Also with a 12 pitch prop and 1.2 gears.
I'm sure everyone already knows you can't have a negative slip except for dguidry. Wut a mullet.

And then u get a 20% slip with his newest numbers. Wut a difference a couple hundred Rpms means.

My skiff runs a solid 30mph at 3900 and 28mph at 4100.I think it has something to do with more efficent use of the prop.

How do you know if your prop is slipping?