what to mix gas on 58 evinrude 35hp

I hear alot of different opinion's on these old motor's people say 24/1 is the right mixture? But people say could go 40/1 with the better oil's we have these day's anyone ever tryed this or am i better of to stick to 24/1 any info would be helpfull thanks in advance

Re: what to mix gas on 58 evinrude 35hp

do not mix that motor at 40:1, my smaller omcs from that era are 16:1, but yours could be 24:1...... 40:1 is just looking for major troubles.

Re: what to mix gas on 58 evinrude 35hp

The secret is in knowing exactly what kind of bearings exist on the moving parts of the engine ie wrist pin, con rod to c/shaft, main bearings, etc OR does it have a babbit like bushing bearing somewhere. Your engine incorporates all needle, roller, and/or ball bearings on its moving parts. As such, you can safely use the 50/1 mixture.... 1 pint of good quality 50/1 oil to 6 gallons of gasoline. A gas octane rating of 87 will be fine.

Re: what to mix gas on 58 evinrude 35hp

take this for whats its worth, but its copied directly from the evinrude website. ( not sure what "generally true" means?)

The following is generally true: 1958 and prior used 20:1, 1959 thru 1963 used 24:1, 1964 and newer use 50:1. High performance usage (racing) requires a ratio of 25:1. New engine break-in (not DI) requires 25:1.

Re: what to mix gas on 58 evinrude 35hp

I think it means be very careful. You have to analyze each motor to see if all of the bearings are there. It really doesn't hurt to run those old ones at 24:1 either. New oil is certainly better than the old straight 30 weight as far as coking up and fouling plugs. My little 3hp's get 20:1 every time.
It's like the difference between a 1963 and 1964 40hp. There is none, yet one is a 24:1 motor and the other is a 50:1 motor.

Re: what to mix gas on 58 evinrude 35hp

tx1961whaler said:

I think it means be very careful. You have to analyze each motor to see if all of the bearings are there. It really doesn't hurt to run those old ones at 24:1 either. New oil is certainly better than the old straight 30 weight as far as coking up and fouling plugs. My little 3hp's get 20:1 every time.
It's like the difference between a 1963 and 1964 40hp. There is none, yet one is a 24:1 motor and the other is a 50:1 motor.

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so...if you were the op, would you go with 20:1, 24:1, 40:1 or 50:1 ? ( i know this subjects been beaten to death in other posts, but still curious about the " modern oil" thing)

Re: what to mix gas on 58 evinrude 35hp

While I don't disagree with Joe Reeves about the mechanical characteristics, maybe even the lube mix, of your '58 'Rude, I find no published official recommendation for that engine for a mix leaner than 24:1. Every OMC or BRP publication calls for either 20:1 or 24:1.

Were it mine it would get 24:1. Style of bearings just might not be the ONLY reason to specify fuel mix.

Re: what to mix gas on 58 evinrude 35hp

nwcove said:

so...if you were the op, would you go with 20:1, 24:1, 40:1 or 50:1 ? ( i know this subjects been beaten to death in other posts, but still curious about the " modern oil" thing)

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Me? A 1958 35hp would get 24:1 of good old TC-W3, 87 Octane ethanol with a shot of Sea Foam and Sta-bil

Re: what to mix gas on 58 evinrude 35hp

Ill throw in my 2 cents here.

I have quite a few 35hp motors from the mid to late 50s, somewhere around 20 I think. I run them all at 24:1. Are todays oils better than they were back in the day? Well yeah they are, and because of that they foul less plugs, smoke less and burn much cleaner, those are the benefits as I see them. Not that I can run my motors leaner on them.

I find/search out many motors a week. I seem to find better results with the motors that havent been run in decades, BEFORE people heard about running at 50:1. The motors with updated ignitions that have been run lately I usually pass on, mainly because of the fear of an owner running it at 50:1.

Might a motor run fine, for a year or more at 50:1? Yes, might be fine. I have this crazy fantasy though that my kids will be running my old antiques when they are my age, and their kids after them. Will that powerhead be as bulletproof in another 50 years at a 50% leaner mix than it was reccomended to run at by the manufacturer? Im pretty confident in saying that I highly doubt it. For that reason I run my motors at 24:1, with some SeaFoam or Carbon Guard as extra insurance. I inspect them quite frequently and can say that due to the noted increase in quality of the oils carbon buildup is minimal and the powerheads are in excellent shape.

Another reason being that these motors are getting to be harder and harder to find. More and more are getting turned into parts motors, or worse yet scrapped for a few bucks by junk collectors. These outboards are going to be harder to replace a powerhead on in another 50 years. Lets preserve these outboards that are loved by so many collectors, myself included, and let generations after us enjoy them as much as we do now ourselves.

Re: what to mix gas on 58 evinrude 35hp

Yep, I agree. 24:1 on 10hp and above. 16:1 on 7.5hp and smaller OMC's The 10's had bronze bearings in the wrist pins, but were good on 24:1. The 18"s and bigger I believe were completely needle bearing from 1955 and later. I happen to own a few of these Big Twin class motors myself. Not 20 like Chris here but I have a few myself. Excellent motors and very reliable. It's amazing how much abuse these things have takem and how well they respond to a complete tune up. Myself, it's my favorite OMC motor.

Re: what to mix gas on 58 evinrude 35hp

ok thanks very much ill go at 20/1 should be safe then