TOPIC:

Just my .02
I've run 40:1 synthetic and non ethanol, everything looked perfect when I opened her up to do crank seals. Compression is high enough I wouldn't want to have to use the recoil starter.
I'm no petroleum expert but oil technology has come a long way since the 1950's.
My 50's vintage chainsaws do just fine on the same mix.

Hawk eyes wrote: Steve, Why are you running 50:1 with the Johnson's and 32:1 with the Evinrude?

Marc,

Where I keep my boat they used to sell 50:1 and that is what we always used for these old motors.

I figure the manufacturer knows more than the guy on the street. Evinrude recommended 24:1 gas to oil mix for the 1957 outboards. That's what I run. My 1968 Lawn Boy lawnmower recommends 16:1 and that's what I run in it. Newer motors that take 50:1 seem to always be needing a top end rebuild.

i too dont know enough of todays oil........Wayne, has mentioned too me he runs synthetic, if i recall riight..........what the difference makes i not know me......he would be a good guy to ask, maybe he will see this thread and add his advice

A scientific study of the lubricating properties of mid-50's oil vs current synthetics would be nice to see. My feeble old brain is trying to remember if I have seen such a thing. Seems familiar, but I lived through the '60's and '70's, so some of my memories are a bit foggy, if you know what I am saying...

VinTin wrote:

piperj3 wrote: What oil and mix ratios do you guys run in the 57 Big Twins

24 to 1.

The newer 50 to 1 motors in their manuals suggest 25 to 1 if they are going to be run at high rpm for lengths of time.

Almost any 2 stroke will run fine on much less oil than their recommended oil/gas ratio. The damage being done is not detected until the motor fails and/or is torn down. They will even run fine with no oil for a little while.

i think Dan and Merky sum it up.........they is what they is.....24-1........put a reclaim on if you don't like the rainbow....i have done my part, doing so, i am happy ...........i can sit at a dock and see minimal to no oil slick while i idle away.......the bushing/bearing technology of the day needs the oil to make them go another 60 yrs, ok maybe another 70, ......lean the mix out, i believe your motors life is shortened..........just my 1.65 cents worth.....

After trying 24:1 in my 59 35 hp Johnson it would not run and smoked like crazy, to a point where I couldn't see anything behind my boat when it did run. I started dropping my oil mix a little at a time and am thinking I'm at 50 to 1 however baseball season is in full force and haven't been able to test anything lately. I was thinking the upper unit may be a newer model but after reading that your running 50 to 1 Steve I think it must be what my motor likes. I was also thinking the coils could be weak and not producing a hot enough spark as well. Anyway someone who has more info knows better and your advice is always welcome.

Steve, Why are you running 50:1 with the Johnson's and 32:1 with the Evinrude?

I have always ran my 1958 35hp Johnson and my 1956 30hp Johnson at 50:1... My wife's 18hp 1958 Evirude I run at 32:1...

I understand the Russian ratio is 40-1.