73 6hp Evinrude Propeller options...

[1BadTitan]

A few guys here at work were telling me that different props will compensate for lower hp motors. I have a 2 blade prop on this motor... Would a 3 blade be better, or a 4. What is the pitch and how do I calculate it? What would give me more power on the water, and are there any negative side effects when upgrading or replacing the prop?

 

[AlTn]

Re: 73 6hp Evinrude Propeller options...

you might want to post this question under Prop Questions and Topics...look at the box with "Quick Navigation" next to it....you'll get great advise on this forum as well....just offering up another option

 

[wilde1j]

Re: 73 6hp Evinrude Propeller options...

A different prop isn't going to make a very noticeable difference on such a small motor. 6 HP is 6HP, unless it happens to be on a racing hull.

 

[jspansel]

Re: 73 6hp Evinrude Propeller options...

Either way, you need to know what the RPM is while wide open. If your prop is causing too high rpm, you should change it and same for the other end of the spectrum. So as long as you are in the recommended RPM with your normal load, I would not mess much with it.

 

[1BadTitan]

Re: 73 6hp Evinrude Propeller options...

Ok, thanks for the tips.

 

[Willyclay]

Re: 73 6hp Evinrude Propeller options...

I have a 1973 Evinrude 6HP motor that was equipped with a 3-blade nylon 8.125X8" prop when I got it in 1985. The prop carries OMC p/n 385940 but that number does not come up in the BRP/OMC parts sytem any longer. The original factory parts catalog for the equivalent Johnson motor listed the standard prop as a 2-blade 8X7.25" prop with material not identified which was OMC p/n 385319. A bud at work had the same motor on his 27foot sailboat for auxiliary power and he used a 3-blade prop with the numerically lowest pitch he could find but I don't remember the actual number. Good luck with that great old motor!

 

[1BadTitan]

Re: 73 6hp Evinrude Propeller options...

thanks guys

 

[F_R]

Re: 73 6hp Evinrude Propeller options...

A sailboat is kind of a special application. There, you need a lot of thrust, and speed is not a concern. If you are dreaming of making your 6 a go-faster motor on a "normal" boat, well.....you might luck out and get an extra MPH out of it but you won't be able to tell without a GPS. In other words, save your money for something else.

 

[1BadTitan]

Re: 73 6hp Evinrude Propeller options...

thanks, that was my concern. Guess it wont happen.