Replacing Prop

[Gone Postal]

I have a 21 Foot Pontoon with a T50 Yamaha Outboard.
Current Prop is 3 Blade AL 14 X 11.
Max Rpm is 5500 RPM
WOT is 4300 RPM
Running by GPS. is 17 mph
Should I drop a Pitch to a 14 X 9 to increase RPM.
Go to a 4 AL Blade if so what is a Recomendation size and Pitch.

Thanks Tim

 

[Don S]

Re: Replacing Prop

You have engine problem, not prop problems. changing prop pitch will get you about 200 rpm per inch of pitch.

 

[SparkieBoat]

Re: Replacing Prop

I agree with Don...you got some other problem..
I have a T60 with that same prop on a 24 toon, it goes 18MPH and turns over 5500 RPMs.

 

[Gone Postal]

Re: Replacing Prop

Well I went with same prop. 14X11 SOLAS . With new prop. I go 18 MPH at 4800 RPM. would like to try a 14x9 to see what it runs at.