RPM at WOT on a 1979 Evinrude 115?

[anderso8623]

What should my RPM's be at WOT on my 1979 115 Evonrude? I am reading 4800-5000.

 

[sutor623]

It should say it on the serial number plate on the main mount

 

[racerone]

I like to run those at 5325 RPM with a light load.

 

[vdwusa]

I run 6000 RPM with a 13x19 pitch on my 115, which probably doesn't help you but I'd ask your local mechanic. You don't want to starve it but you don't want to lug it either...$50 is a cheap spare prop.

 

[Chinewalker]

I would prop it to peak 5800-6000 with a light load. Those V4s do not like to be lugged, and peaking around 5000 is lugging... My 1984 Johnson 90 hits 5900 with just me in the boat.

 

[V153]

I would prop it to peak 5800-6000 with a light load.

Yup.

 

[tblshur]

im sure these guys know from experience what works best, i take experience any day, however my omc sm says my 83 140 wot should be 4500 to 5500. :joyous:

 

[V153]

im sure these guys know from experience what works best, i take experience any day, however my omc sm says my 83 140 wot should be 4500 to 5500. :joyous:

That's "optimum operating range". Not "redline". Manufacturers don't offer you a redline. They prefer to be vague. But 5900 to 6K wide open with a light load is perfectly acceptable. And that's what you should prop for.

Not to suggest you run it there all day every day ...

 

[anderso8623]

Thanks guys!

 

[anderso8623]

14 X 17 is what is on there now, if I go to 15 I'm still only pushing 5400. Should I drop to a 13 pitch? With the prop I have now, again, 48-5000 and about 33.5 mph.

 

[V153]

Before we go any further ... What kinda boat's it on?

 

[anderso8623]

1983, 17ft mako

 

[racerone]

There may be something wrong with the motor.-----Have you done a compression test ?----Going to a lower pitch to get the revs up may mask an issue with the motor !!