What fuel mixture for a old saw

[ifixoldjunk]

First off, this would be my first post on this site so hello, And secondly, I've recently started collecting antique chainsaws. I know back in the day fuel mixes were regular motor oil and gas so the ratios were like 16:1 or 32:1
I know modern oil is more advanced so I am wondering if 32:1 is overkill on my old super xl automatic, I've been told 40:1 or 50:1 is pretty much universal anymore I just don't really feel like testing that on my old saws though. In the same breath for having been a small engine mechanic for quite some time I know an excess of oil is just as bad because carbon deposits can wreck your engine.

edit: at my old shop the official policy was 50:1 for anything two stroke, and it never seemed to harm anything. We had a repeat customer with a vintage lawn boy we would service, along with the service came a fresh tank of gas and it never seemed to damage it.

[blythkd]

I wouldn't worry about running 40:1. I ran 40:1 Homelite ExactMix for years until I could no longer get it. And I was running it in multiple Super XL's.

Many are now running synthetics at 80:1 and even 100:1 with no problems.

[w30bob]

Hi ifix,

I'm relatively new too, but welcome! I run everything on 50:1, as the oils today are worlds better than what was available back in the day. I work for the military on 2-stroke drone engines and when we run kerosene based fuels (diesel, jet-A, JPs) we've run 2-strokes for hours and hours on straight fuel....no oil at all. That won't work for gasoline, but unless the piston to wall clearances are super tight they're fine on 50:1. I always find it amazing that they didn't really have dedicated 2-stroke oils until the mid 60's when the outboard guys led the way. Every time I read the gas caps on my old Homelites saying to mix in some 30W motor oil I just have to smile. What a different world it was back then!!

regards,
bob