sthil 090 fuel mix ratio

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injun joe

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ok recently read that the stihl 090 takes a 20:1 mix is this possible and if so why is the mix so thick. couldnt you run 40:1 or even 50:1 and still be fine.
 
090 brochure i have in front of me says

"mixing ratio 1:25 when using two stroke motor oil of viscosity class SAE 30"

I'm sure using more modern oils you could run 40:1 or 50:1, but having said that I run 25:1 with husky low smoke oil, and it runs great, doesn't foul, smoke or have any dramas, I figure its safer to run 25:1 so I stick to it.:chainsaw:
 
Well, that is a valuable saw. You might want to consider running 1:1 for extra protection. :popcorn:

lol yeah it is my dream saw. yeah i think ill start running 16:1 cuz i have 3 different saws that will run on it and theres to much math involved for 20:1.
 
Yea I really couldn't see that you'd have a problem with 40:1, that many people have ran that and leaner and you just don't see people posting photos saying "look, heres my saw which stuffed up running whatever:1"

Unless i'm on the wrong track - larger lower revving 2 strokes (in motorbikes at least) often run a leaner mix than small high revving ones.

I only run what i do because thats what i'm comfortable with, don't matter too much aftermarket 090 p&c kits have become fairly easy to come by.
I'd be just using whatever you run your other saws on, otherwise you just end up with too many cans of fuel around!:givebeer:
 
090 brochure i have in front of me says

"mixing ratio 1:25 when using two stroke motor oil of viscosity class SAE 30"

:

This recommendation of 25:1 is for vintage oil......running modern synthetic oil at 40:1 or 50:1 will be just fine in your old saw. There is no need to run 16/1, 20/1, 32/1 unless you are using vintage SAE 30 oil!
 
:greenchainsaw: alright that clears things all up. now i dont have to carry around 3 gas tanks just the 40 and the 50:1. well i ran 4 tanks through the 090 and cut good just wanted to make sure i wasnt doing and fatal harm to it.
 
You ain't wrong Brad... Heck I use 50:1 full synthetic in ALL my saws... whether they are 40 years old or 4 years old... no probs... :)

Gary


:agree2: totally, the ol' specs is due to oil quality, not P&C quality - at least in the better saws, from about 1970 or newer - most likely further back as well.....:chainsawguy:


50:1 rulez!!!!!
 
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ok i have one question the stihl oil that comes in the white container to mix is that synthetic. i didnt think it was just because it didnt say or is that just something that was a given and if it isnt should i still gowith the 16:1
 
Just reading through this 2009 thread . I've acquired a 1995 090AV this morning , and I think I'll go with 40:1 Stihl synthetic .
 

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It's put together from the best of three , but has a new handle and side covers from Canada ( possibly , I'm guessing ...... ).
The bar and chain are new . As you're aware , the current 404 bars have the tensioning holes in slightly different positions to the discontinued 404 bars , so it's been drilled to accommodate this .
It's in wonderful condition and was a collector's show-piece . I thought my MS660 25" was heavy enough , but this is something else . All the guys in the street have been over to see it.
We're covered in 08s around these parts :) , but bigger old stuff is not so common . I paid USD1350 for it plus $50 freight. When I started her up , she was glorious . What a saw !
 
08's are not that common here. I have a very nice original from 1966. Like the looks. Kinda like the 090. I need to fire up that 08, its the one, that started this CAD craziness.:chainsaw:
 

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