15" or 17"

[stemar]

Hello<br />Can you please tell me how much diffrence in speed I will get if I change my 13-1/4 17" pitch prop to 15" pitch. I now reach 35mph with my 90HP Mariner outboard on 17 feet boat. It pulls my self on slalom ski easy but I don't get enough speed. <br />Thanks

 

[Jack Shellac]

Re: 15" or 17"

I have a similar setup to yours and also have 17" and 15" SS props. I pick up 500 RPM with the 15" but lose 6 MPH of speed.

 

[Boatin Bob]

Re: 15" or 17"

Going from a 17 to a 15 will drop your top end speed but will improve your hole shot, what you have to be careful of is that you don't exceed the WOT recommended RPM range for your motor, going to a smaller pitch prop will increase your RPM's by roughly 200 for each inch of pitch you decrease.