Re: what does the prop diamiter do?
Prop diameter is a secondary consideration.Not directly addressed except incertain specific applications.Increasing diameter may reduce rpm slightly unless in the extreme say an inch then rpm reduction may be noticeable. as much as a couple of hundred rpm.
A larger diameter may help resist venting on difficult applications like a pontoon.
Reducing diameter may increase rpm slightly.
If you check prop sizes on the prop store page you will notice that generally as you increase pitch diameter goes down and the opposite when pitch decreases.
If you add a blade diameter goes down.Diameter is just the result of the prop design.
If you look up props intended for your motor you can pretty much ignore diameter. Certain designs might require you to change the anode for more clearance but that is usually more from blade design than diameter.
