Fish-Hawk.Net

Looking for someone to help me out with fitting a proper prop on my boat. I have been struggling with it for a while. I am taking the boat out on Sat and hope to figure out what prop I need. From what I remember last year the 19 Pitch that I have on it would run me at 5500 rpm. 3-4 second hole shot but not allot of top end speed. Found out over the winter that my WOT rpm should be 5000 rpm.
If you can help me figure this one out send me a text 613-281-8409
thanks
Derek

First make certain that the motor was installed at the right height on the transom. Then out on the water go WOT trim the motor properly and check your Rpm.

I've just made changes to my pitch, never tried going from a 3 to a 4 blade prop or changed size of prop.


Then every drop of 1 inch of pitch your RPM will go 200 higher.
or

Then every 1 inch of pitch higher your RPM will drop by 200. to hit the 5000 WOT RPM

I have raised my motor as far as I can without it cavitating. I was able to get that figured out at the end of last year. I played with props for 2 years before I learned about raising the motor, and about my motors preferred WOT RPM . looking back at my notes I was able to get it to 43 mph
Thanks for the tips. I will be checking it on the water on Sat

What motor do you have and can I assume it's pushing a Boston whaler?

Wallayebosses info is a great rule of thumb but It isn't always the case. Sometimes you will get less tha. 200rpm difference between prop pitches.

I know, I would have assumed a whaler as well. My first boat was a whaler, this one is a sd80fs skeeter with a 90hp V4 evinrude. ( both are 1985)

Was to windy to go out today. But I was able to swap my cranking battery to one that was almost 30lbs lighter. My old one was almost 70lbs. Because of changing the battery I was able to shift it forward over a foot in my rear compartment. Hopefully this helps as well.