Stihl 090 gas question?

[teddy]

What is a good ratio for a 090? 50:1, 40:1????
Thanks Matt

[Rockfarmer]

Best not to mess with that old saw, send it to me and I'll take good care of her  :D :D

[Rocky_J]

Exactly the same as any other chainsaw. The metal parts in the motor don't care what the ratio is, they care what the lubrication level is. If you want to time-transport back to the 1960s and retrieve some of the motor oil they used back then, then you would need to mix a lot of that oil with gas in order to provide enough lubrication to protect the motor from wear. Today's oils (especially the synthetics) can provide many times the amount of lubrication with much less oil. Using a good synthetic at 50-1 will provide much better lubrication than using 1960's era 30 weight oil at 16-1.

So regardless of the saw, any time anybody asks "What is the best mix ratio for XXXXX saw", the answer is exactly the same.

[GASoline71]

To mirror what Brian said... I have saws that are over 30 years old that I run on 50:1 Stihl Ultra.  Full synthetic.  I run al my saws on that same ratio... whether the are 3 months old or 30 years old.  If ya wanna run straight 30wt mixed in the fuel like they did back then... then yes... 25:1 or 16:1 is more fitting.

Gary

[Al_Smith]

Oh goody the oil wars again  :D

Any good mix oil anywhere from 32 to 1 or 50 to 1  ratio .Being somewhat of a  black powder mind set I prefer the heavier mix but for the sake of simplicity will just let it go at that . 8)

[teddy]

Thanks Brian, Gary and rockfarm!
That's what I needed to hear!

[beenthere]

Good thing that new people have a place to come to discuss the oil mixes. Lots of heresay and other information kicked around. Some is good, some not.

FF is the place.  8)

[jacob j.]

Just as important as the oil ratio is to make sure the fuel system is well maintained, the carburetor is in good tune so the engine is getting plenty of gas/oil, and that you watch the RPM if the governor has been defeated...