24:1 or 32:1?

MN_fisherman

Cadet
Joined
Mar 4, 2008
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21
Well I got my 57 sea king 3 hp running last night for the first time in 28 years. After some adjustments to the carb she idles and runs great. But does it smoke!! I've read a few posts concerning that ratio of oil to gas and seems that most agree that 24:1 is good for this motor. It seems that a least a few folks think that 32:1 is OK though as well. I plan to use this motor on a 17' flat back canoe for river fishing and duck hunting and imagine that most of the time I'll be running it a less than WOT. Does anyone have any first hand experience with running these motors on 32:1? Will I even notice a difference in the smoke by cutting back from 24 to 32:1? Has anyone here ever ruined an outboard by using less than 24:1? I'm just looking for people that have had experience with the type of outboards.
 
D

DJ

Guest
Re: 24:1 or 32:1?

My '57' Evinrude 7.5 calls for 24:1. I run it at 32:1 or slightly less. No issues whatsoever. Yes, it smokes less.

Todays oils are a lot better than in the 1950's. At that time they called for straight 30 weight automotive oil.:eek:

I don't want you to blow up your engine. Run it at 24:1 and consider "synthetic" oil. "Syn's" smoke a lot less. For the small amount you're going to use, don't let the price scare you.
 

F_R

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Jul 7, 2006
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28,226
Re: 24:1 or 32:1?

24:1 is already cutting it from the original 16:1. Don't try running on less than 24. That is what I run in mine. To be more than honest, I tried it on 50:1 and it didn't run as fast. Figured it was time to stop that nonsence before a rod came through the case. I suppose you were were running it in a barrel? It will be MUCH cleaner on a boat.
 

JB

Honorary Moderator Emeritus
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Re: 24:1 or 32:1?

What F R said. ^
 

steelespike

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Re: 24:1 or 32:1?

I am just repeating the info in my Aftermarket ser. manual (covering 55-63 3 hp).Not saying one way or the other.Manual says 24:1 Using using outboard or sae 30 oil.Perhaps 32:1 could be used with TCW3 or synthetic.. But considering the risk if too lean
I think I would rather use synthetic at 24:1.Smokes less,fouls less and is said to be biodegradeable.
 

rolmops

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Feb 24, 2002
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5,518
Re: 24:1 or 32:1?

I am just repeating the info in my Aftermarket ser. manual (covering 55-63 3 hp).Not saying one way or the other.Manual says 24:1 Using using outboard or sae 30 oil.Perhaps 32:1 could be used with TCW3 or synthetic.. But considering the risk if too lean
I think I would rather use synthetic at 24:1.Smokes less,fouls less and is said to be biodegradeable.

Although I do run my 1957 35 horse Johnsons at 32:1. It might not be such a good idea to run the smaller engines with that mix.It is my understanding that the smaller engines did not get equipped with needle bearings until 1963 and the smallest ones not until the seventies.
 

tmcalavy

Rear Admiral
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Aug 29, 2001
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4,005
Re: 24:1 or 32:1?

24:1, preserve the bushings...don't think it has bearings. Bushings require more oil because the oil serves as a bearing, but isn't...oil is cheap, rebuilds aren't.
 

wbeaton

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Jul 30, 2006
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Re: 24:1 or 32:1?

Use synthetic oil at 24:1 and you will notice there is very little smoke and no oil sheen on the water. Id' compare the amount of smoke to my 1988 Johnson 30 hp running 50:1 conventional oil.
 

MN_fisherman

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Mar 4, 2008
Messages
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Re: 24:1 or 32:1?

Thanks for everyone's input, I was running the motor in a barrel and I was shocked by how much oil residue was left after running for a relatively short time. I will stick with 24:1 and give the synthetic oil a try. Part of the reason for all the smoke and oil residue may have been the fact that the rings were stuck when I first tried the motor and I had sprayed a bunch of fogging oil down the cylinder to loosen things up. I'm not willing to risk burning the motor up even though my guess is for the way I will be using the motor (trolling) I'd probably still be okay at 32:1. Thanks again!
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: 24:1 or 32:1?

Tsk, tsk, Bro Haut. Hijacking MN fisherman's thread.

Your '68 will do fine with 50:1
 
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