Just follow Skybolts direction to get your baseline. Assuming your current prop puts your WOT at the high end of your motors recommended RPM range you can then make an educated guess on what prop to try. Generally lower pitch by 2 degrees when moving to a four blade. This should keep your RPMs...
Also allows you to stay on plane at a lower speed. Reduces low speed wander a little bit. I prefer 4 blades as I don’t care about top speed as much as the other benefits over 3 blades.
In addition to Skybolt’s very excellent explanation of determining the baseline for the current prop, I would also use a GPS app to to gather top end speed. Top speed might not be your end goal but having another data point to compare can be helpful when making a prop change.
Pretty sure it was actually a WWI theme. At least at Palwaukee. I thought it was cool that each table had headphones so you could listen to the tower chatter.
Jim, I was trying to agree with you. There are lots of reasons people pay a mechanic to do the work. That doesn't make them less knowledgeable. I think that was your point.
I think Harry also said, "a man needs to know his limitations." I've done many upgrades and modifications to my boat(s) over the years. Just like many of you on this forum, I know what I'm capable of and am willing to share advice when I can. I know how to winterize my block but still pay the...