Prop Upgrade on 75 HP Evinrude

[Bigbobdallas]

I have a 20 foot Pontoon that has a 75 HP envinrude on it. Year boat and motor is 1989.
What is the best all round prop size to have to get max speed and good hole shot. And best for crusing

 

[Silvertip]

Re: Prop Upgrade on 75 HP Evinrude

Go to the PROP FORUM and right at the top of the forum is a sticky title READ THIS FIRST. It tells you what we need to know in order to even guess what you need. You gave us absolutely nothing to work with. The best prop is one that allows the engine to operate at or very near the top of the manufacturers recommended wide open throttle rpm with what YOU consider an average load. Too little pitch and you overrev. Too much pitch you lug the engine. When pitch is right, speed will be what that prop provides as will hole shot and economy. For all you know you have the best prop.

 

[EGlideRider]

Re: Prop Upgrade on 75 HP Evinrude

^^^^^ +1 ^^^^^

 

[lmuss53]

Re: Prop Upgrade on 75 HP Evinrude

I agree with what you've been told 100% but will ad that you don't want to just run the 75 without making sure you are within the recommended range.

I took a 75 OMC off of a 17 foot runabout and put it over onto my 24 foot Manitou a few years back. We took it over and went for a test cruise with 4 guys on board and ran it at wide open for about 10 minutes at what was obviously below the 5000 rpm recommended minimum. I know today that that caused a lean condition and scored a cylinder wall, result one blown 75.

Make sure whatever prop you start off with lets you get out to at least 5000 rpm at WOT. I would think that would be at the maximum a 15 pitch prop. I had a 13p on my 20 footer with a 90hp Johnson earlier this spring.

Evinrude did not make a 75 HP model in 1989, last one if it's a v4 is 88. No biggie but I thought you'd like to know.