Porpeller pitch help, changing from a 17 to 15 pitch ?? (boat pictures)

[monoshock]

Hello, I working on my father-in-law's 15' older tri hull w/1988 Evinrude 48HP SPL, that is used for fishing. The prop on it is beat up badly. Running a 13/4x17 now. If I replace it with a 15 pitch would that make the motor over rev? The boat doesn’t have a tachometer. The reason for asking about changing the pitch is Iboat has close out deal on a SS 13/4x15, they don’t have a 17 pitch on sale just a 15 pitch. If the 15 pitch won’t work I will get an aluminum one with the same pitch.<br />

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<br />Thanks for your help.<br /><br />Here's the link for the 15P prop.<br /><br /> http://www.boat-props.com/propeller...vinrude/rotation-Standard/chart-14/index.html

 

[craze1cars]

Re: Porpeller pitch help, changing from a 17 to 15 pitch ?? (boat pictures)

The only way to answer this question is to know your current WOT RPM's, and the recommend max RPM range for that motor. Put a shop tach on the motor and take a test-drive with the current prop, then someone here can help you make a decision. If I'm not mistaken, I believe going from 17 to 15 will likely increase your max RPMs by about 350 to 400 rpm. But that info is useless is you don't know what the RPM is anyway. Enjoy your project!

 

[KCLOST]

Re: Porpeller pitch help, changing from a 17 to 15 pitch ?? (boat pictures)

I'd stay with the same pitch if possible... It's gotten you this far and as Craze mentioned, it is hard to tell what will happen with a different prop unless you have rpm data in reference to what is recommended for that motor...

 

[Perfidiajoe]

Re: Porpeller pitch help, changing from a 17 to 15 pitch ?? (boat pictures)

Why not see about getting that prop repaired? At least get a price to repair it may be the way to go

 

[monoshock]

Re: Porpeller pitch help, changing from a 17 to 15 pitch ?? (boat pictures)

Thanks for the help, I suggested repairing the old prop, but he wants a new shiny one like the one I just put on my pontoon boat. He said it would probably out last him. I guess I’ll order the aluminum one with the same 17 pitch; I don’t want to mess with the r.p.m.’s . <br />He’s on a fixed income and I’m just charging for the parts for the repairs on his motor. He took it to a local shop a few times last year and they charged $135 to install a water pump impeller, and just quoted him about $200 to rebuild the carbs. I told him to bring it over and I'll fix it.

 

[CalicoKid]

Re: Porpeller pitch help, changing from a 17 to 15 pitch ?? (boat pictures)

Good man

 

[macjsm]

Re: Porpeller pitch help, changing from a 17 to 15 pitch ?? (boat pictures)

I would stay with the 17

 

[Solittle]

Re: Porpeller pitch help, changing from a 17 to 15 pitch ?? (boat pictures)

mac - Take a look at the date of this thread.