What prop and RPM for Evinrude 65?

[mmurray70]

What RPM should i be running with my 92 Evinrude 65 hp? Manual says 4500-5500 but after doing some reading on here people seem to suggest all sorts of things for these 60/65/70hp engines. Saw some people suggest 5500 mininimum. What should i aim for?

Also what do you guys suggest for a prop? This engine is a little small for my application. Its going on a 20 foot V-hull, side console fishing boat. Total weight is around 2000 lbs.

 

[flatsider45]

Re: What prop and RPM for Evinrude 65?

If the manual says 4500-5500 I'd stay with it.That's not a light boat and I don't know what diameter and pitch you have on it now,but you're gonna need a pulling prop for sure.(smaller pitch).Just remember for every inch of pitch up you will lose about 200 rpm. and vise versa.It's basically a trial and error and can get expensive,so try to find a dealer that would work with ya with maybe some used props to find the right combo,but do stay within that target range because you dont want to load the motor too badly(not enough rpm) or turn the motor up too much.Either way can cause serious damage. Hope this helps. good luck!

 

[steelespike]

Re: What prop and RPM for Evinrude 65?

Run it with your present prop.get us the prop size,max rpm and speed.
It will almost surely need a prop change these figures will help tell where to start.

 

[mmurray70]

Re: What prop and RPM for Evinrude 65?

I was hoping to try it this weekend but we had high winds.

If I am low on rpms like I am expecting can I continue using it the way it is or should I wait? Is it hard on the engine to be overloaded like that?

 

[steelespike]

Re: What prop and RPM for Evinrude 65?

If it seems to be responding normally but just not making the rpm range
Using it for a weekend or 2 won't hurt.It may help you get a better feel for what you need.

 

[mmurray70]

Re: What prop and RPM for Evinrude 65?

Hey guys I got some numbers for you to look at.

Engine came with a 15" prop but it was a big load on the engine with this heavy boat. Didnt rev high at all, seemed to be straining. I picked up a 13" pitch prop and installed a tach at the same time.

Tried it today and im maxing out at about 26mph and 5600-5700 rpm. At one point when I had the passenger towards the back it crept a little higher, maybe 5800 or so. Cruises nice around 22mph at around 5000 rpm.

Im happy with the way it runs now. But I am a little over the reccomended range. They reccomend the 70hp to run 5000-6000 so the crank and stuff should be able to take it i guess? You guys think Im safe to run it that high? Should I try the 15" prop again now that I have a tach or just leave it?

 

[Dhadley]

Re: What prop and RPM for Evinrude 65?

The rpm range at which those motors are rated at isn't necessairly the rpm range that they will live the longest at. With todays fuel you are right where you want to be. Nice job on making sure things are right.