Performance numbers

[FishStretcher]

Props confuse me
A 13.75 x 19 or a 13.5 x17? The second is less RPM and less pitch than the first. Maybe this is the range you think I will be in?

There is a 4 blase SS Yamaha 13.75 x 18 for sale locally. $275 asking price. Not sure if it will fit my gearcase. It fits the F150.

Also, how do you like the hydroshield?

2000 Yamadog F100: 2.31:1 gear ratio, Max of max rpm is 6000.

Assuming you're getting a true 100 hp, then you probably need a 13.75"D x 19"P, or a 13.5"D x 17"P to be able to turn 6000 rpms fully loaded (or close to it). You should have a top speed in the 32-35 mph range. I would try to start with a 19"P prop.

Rremember: More pitch = less rpms. You could get by with a 13.25"x20"P or maybe even a 13.25"x21"P, but the Yamaha F100 is NOT known to be a torquey motor.