Im looking at getting a 3 blade prop and need some help on which pitch i need. Its going on a F115 yammy. How do I Calc. the pitch needed? I have a 4 blade on there now and my hole shot is bad at times. I was thinking try a hydrofoil first then get a 3 blade. Any thoughts?
“My fish served a whole lunchon. Your fish look like a munchkin”
167 Ranger Cayman
Yamaha 115
“Hydrophilic”
2007 Toyota Tundra TRD 5.7L V8
GO PIRATES!
What diameter & pitch prop do you have on there now?
How many RPM’s is your engine currently turning at WOT and what is the max WOT for that motor?
The 4-blade should give you a better hole shot IF it is the right pitch and only reduce your top speed by 1-2 mph compared to a properly sized 3-blade. Whichever prop you choose, you need to make sure your motor will turn up to the max WOT. Otherwise you are overloading the motor which isn’t good for it.
There are some prop selector guides on the Internet that get you “close” to what you need. FWIW, I ran a 14x19x3 AL on my Key West with a 115 Evinrude 2-stroke and changed to a 13x19x3 cupped SS prop which gave me a better hole shot, cruising speed and top end.
I have three props for my boat now and all three will work, just one works better than the others 
