1976 Evinrude 70 HP full throttle RPM question

[1kruzer1]

I'm asking for opinions on what full throttle RPM I should be striving for on my 1976 Evinrude 70 HP. Factory specs from '76 state operating range is 4500 to 5500 RPM, but I've had a couple people tell me to run a little higher or I'm actually lugging this engine. With my current prop I get 5350 RPM with my normal load. Dropping one step in pitch on a prop would probably put me at 5700 to 5800 RPM. I do not want to shorten the life of this old motor by over-revving or lugging. What do you advise? Thank you.

 

[5150abf]

Re: 1976 Evinrude 70 HP full throttle RPM question

Sounds like you got it about perfect to me, I wouldn't mess with it at all.

You do not want to over rev the engine, check back with that guy in a year and see what he thinks about that little theory.

The engineers at OMC are way smarter than any of us so if they say 4500-5500, that is what you should run, 5350 is perfect.

 

[1kruzer1]

Re: 1976 Evinrude 70 HP full throttle RPM question

Thanks! That's always what I thought as well. The recommendation was regarding this specific model and year, and that in later model years OMC raised the operating RPM specification on the 70. When I researched it a bit I found that to be true, but they also increased the displacement of the 3 cylinder engine in a re-design, so I didn't think I agreed with applying it to this earlier model.