16:1, 20:1, 40:1, 50:1....... how dry can I run this thing?

[Dave in VA]

The book says 16:1, but that seems like it is a smoke fest with this thing. As a late 70's Roper/Craftsman, what is safe to run in it?

 

[mdavlee]

I run 32:1 in everything

 

[SS Sniper]

If the book says 16:1, then I'd run that or something close to it, but I know nothing about those old saws so take my advice lightly.
Matthew

 

[mdavlee]

If it had open bearings like a Clinton then it needs the 16:1. Other than that a good oil mixed at 32-40:1 will be fine.

 

[SS Sniper]

One would think that what the manufacturer suggests for an oil ratio is what they believe is sufficient for the saw. Whether or not they are right is another story, but I don't think you could go wrong with anything from 16:1 to nothing more than 35:1 would be fine. I'd tune it rich through the carb settings as well. Why don't you run it a bit and find a happy-medium between the amount of smoke and the ratio of the mix?
Matthew

 

[kevlar]

today's oil are far better than they were back in the 70's. you will be fine with 50,40, 32 to 1.

 

[jeff taswelder]

If you run the saw for a while you will find it might clear up as it burns up the old crap out of motor and exhaust.
1 or 2 tanks. usually 1 would do it.
i run 32 to 1 in all my old saws around that age with no prob
New oil today is better than old oil of that time
Oh and that is a very nice saw you have there

 

[Dave in VA]

today's oil are far better than they were back in the 70's. you will be fine with 50,40, 32 to 1.

That's what I was thinking about. Is the trend toward thinner mixes brought on by better oils, better machining tolerances, a search for lower emissions, or maybe a combo of all three? My Ryobi weed whacker runs 50:1, my 1979 Vespa ran 50:1, why is my 1978 saw running 16:1?

 

[jeff taswelder]

emissions
I have read on this site that running 50 to 1 can lead to not quite enough oil getting to the lower bearings .
I would run them at 32 to 1 to 40 to 1 to be safe.
Just my op

 

[wcorey]

Happened to have just responded to a similar question elsewhere so it was easy to just copy paste here also...

It's not the saw that determines the mix ratio, it's the oil, those heavy ratio's are based on what was available when the saw was new.
16:1 would be for 30w motor oil, from before there were readily available dedicated 2-stroke products, 25:1 was typical for many vintage 2-stroke oils.
Most modern 2-stroke oils are formulated to run at a recommended 50:1, though many folks claim that 32 or 40:1 is better for the bearings
and the 50:1 is only to address environmental regulations. It's an endless debate...
If you run a non synthetic at 16:1, particularly with a rich tune, it's likely to carbon things up a lot and can lead to fouled plugs, clogged exhaust screens or even carbon scoring...

 

[treesmith]

Would that have been designed with castor based oil too?

 

[Dave in VA]

Well, considering that the saw sat for the better part of 20 years, I loaded the tank up with a full batch of 16:1 and a table spoon or two of seafoam to help cut the varnish from the evaporated old gas. The more I run it, the better it gets. I'll report back after a full day's work sawing firewood.

 

[jeff taswelder]

I think u will like it

 

[pioneerguy600]

I run 40:1 in all these old saws and they like it just fine,

 

[lone wolf]

I run 40:1 in all these old saws and they like it just fine,

Do you wake up in the morning with your hands asleep from carpal tunnel ?

 

[Festus]

Unless I missed it, I don't think anyone mentioned rechecking your carb adjustments. I would think going from 16:1 to something like 40:1 would make a difference.

 

[Dave in VA]

Unless I missed it, I don't think anyone mentioned rechecking your carb adjustments. I would think going from 16:1 to something like 40:1 would make a difference.

You know, I hadn't thought of that angle. I'd like to hear thoughts as well.

 

[Festus]

By using less oil, you will be using more gas in the mixture. It will probably need to be leaned out a bit, assuming it's properly adjusted now.

 

[pioneerguy600]

Do you wake up in the morning with your hands asleep from carpal tunnel ?

I have carpel tunnel, had it for 30+ years now and limit the amount of time I run old magnesium saws.

 

[lone wolf]

I have carpel tunnel, had it for 30+ years now and limit the amount of time I run old magnesium saws.

Me too.