Correct RPM for 1975 Evinrude 70573-B 70HP

Nandy

Nandy

Commander
Joined
Apr 10, 2004
Messages
2,145
I have a seloc manual and it list it under 5krmp, if anyone has the oem book and can tell me what is is rated max for I will appreciate it. I am around 5450 with this 17p prop at wot doing 30mph. If that seloc book max rps number is correct then im in my way to ruin the motor. I do suspect the number is wrong as this is the same setup the previous owner ran for the last 20 some years before he died and the motor is ok.

I know, selocs are only good for ___________ (insert sarcastic phrase here) but I paid good money for it and it has so far work right. Hard to just eat that money....

Many thanks!!!
 
TN-25

TN-25

Chief Petty Officer
Joined
May 27, 2008
Messages
623
Re: Correct RPM for 1975 Evinrude 70573-B 70HP

According to the Johnson & Evinrude brochures I have around, the 1975 70-horse triple was rated at 70 horsepower at 5000 rpm. Full throttle operating range was 4500-5500 rpm.

It should also be mentioned that in 1975 that very same 49.7 C.I.D. engine was tweaked to create a 75-horse version. The 75-horse was rated at 75 horsepower at 5500 rpm. Full throttle operating range was 5200-5800 rpm.

Clearly you are in an acceptable range, and your motor should be making it?s rated power (whatever method they used to rate it) because the revs are reaching the intended full-throttle operating range. It?s all good!
 
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