Prop Diameter

[rjd]

What effect does prop diameter have? I'm running a Honda 150 with a 14.5"x19P (standard issue when I purchased the motor) and in prop shopping I notice props in the 13.75" to 14 5/8" for my application. Thanks for your input.
New engine break-in period so I don't have Wide open speed but here's the info I have.
19' nitro
150 honda 14.5x19 aluminum prop gear ratio is 2.14:1 I did take it to 6200 rpm briefly without hitting the rev limiter
4k rpm=30 mph
tanks half full (20-25 gals)
hole shot is 3400 rpm's before the nose comes down (I installed wedges which helped) on 5" jackplate
I tried a 14.25"x21 aluminum and it didn't get any bite and I couldn't get on plane
I'm at 3.5" below pad on my setting but tried raising and lowering it 1/2" without any improvements for this prop
I hope this is enough info to give you guys an idea where I'm at in the re-proping process. Thanks for your knowledge sharing.......

[Fatshaft Merc]

You need to forget about the aluminum. Aluminum props don't perform well bassboats. They have little to no cup and the blades flex too much. Try a tempest or a trophy, probably a 21 pitch.

[rjd]

Yep I agree. I'm trying to find the right pitch before I commit to a stainless. Possibly one of Mark's creations.

[Fatshaft Merc]

The right pitch in aluminum is not gonna be the same in stainless.

[mdtritn21]

Break the motor in and run it loaded ready to fish not lite and get some new numbers or you'll end up spending a bunch of money on props. List the model number of your boat too.