Correct fuel/oil ratio for mid 1950’s Johnson

[dshanks]

I recently got my grandfather’s 1954 Johnson QD running again and want to make sure I’m taking care of it. I’ve looked all over for the correct fuel/oil ratio for this motor. Almost everywhere people are saying 24:1 or "minimum 24:1." But I also found (here: http://www.fiberglassics.com/wiki/image … ice001.pdf) a service manual that covers the 1955-1963 versions of the motor. Presumably its advice on fuel/oil ratios is good for Granddad’s 1954 motor too. It says that pre-1959 motors should be oiled at 16:1.

Can anyone offer advise on whether, with modern oil and fuel, I should be running 16:1 or 24:1 in this motor? Is the modern stuff so much better at lubricating that I can safely run 24:1? Or am I risking the motor’s well being and should really run 16:1. Is there some reason I see 24:1 recommended in outboard forums when the service manual clearly says 16:1?

I’ve run a couple of gallons of gas through the motor at 24:1 since getting it running again. I’m hoping I haven’t caused excessive wear by doing so.

Thanks.

[RICHARD A. WHITE]

Did it smoke when you ran it at 24:1 ??? more than likely it did. 24:1 should be good, now on my REALLY old stuff…it get thicker than that…lol

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[retiredoz]

I’d follow the service manual and go 16:1. Even if newer oils are ‘better’ it’s not going to hurt. IMHO, a couple gallons of gas isn’t enough to cause any lasting damage.

[retiredoz]

On second thought, the OFFICIAL Johnson manual says 24:1.

[fleetwin]

I would definitely use the 16:1 mix for that 10hp due to that engine’s tendency of wearing wrist pins.

[frankr]

quote fleetwin:

I would definitely use the 16:1 mix for that 10hp due to that engine’s tendency of wearing wrist pins.

Me too, for that reason. Will it actually help?? I don’t know, but I’d feel better.

[crosbyman]

smoke is good for bugs !

try xd-100 biodegradable if you are going to stink up the lake !

Joining AOMCI has priviledges 🙂

[dshanks]

Thanks guys. 16:1 it is. Yes, the motor does smoke even at 24:1; especially while warming up. Guess I need to find a local source for biodegradable oil.

I’m surprised that one official manual says 24:1 when the official Johnson service manual I found (published by OMC) says 16:1. Maybe OMC engineers eventually discovered less oil was really needed?

Even at 24:1, the plugs (J6C) seem oily. Is that normal?

Funny about the bugs. My father, the motor’s 2nd owner, was an entomologist. 😉

[legendre]

If it were mine, I’d run it at 24:1 with a quality TWC-3 and not expect any issues.

But this isn’t my motor.

[frankr]

quote dshanks:

Thanks guys. 16:1 it is. Yes, the motor does smoke even at 24:1; especially while warming up. Guess I need to find a local source for biodegradable oil.

I’m surprised that one official manual says 24:1 when the official Johnson service manual I found (published by OMC) says 16:1. Maybe OMC engineers eventually discovered less oil was really needed?

Even at 24:1, the plugs (J6C) seem oily. Is that normal?

Funny about the bugs. My father, the motor’s 2nd owner, was an entomologist. 😉

I can show you an official Johnson service publication that says 50:1 is ok. But that is ONLY if Johnson oil is used. Now, that original Johnson oil is obsolete, and is today’s oil the same thing? Good question, huh? I guess you decide. But for me, on that motor with it’s known wrist pin problem, I’d use at least 24:1 or more.

Sure, the plugs will be oily. Especially after running at low speeds. That’s just the way it is.

You suggested that OMC engineers discovered that less oil was really needed (?). Matter of fact, I heard that directly from one of them at a service clinic when 50:1 was introduced.

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