# 40 to 1 mix ratio



## SteveG (Mar 2, 2010)

Before getting my next chain saw gas I hope to get some advise as to mix ratio. I think it was in this group I've seen reference to a 40 to 1 mix ratio instead of the normal 50 to 1 for the Stihl but can't find the threads to re-read the reasoning behind this. I buy the hi-test gasoline and usually mix the 5.2 ounce bottle to 2 1/2 gallons. My 361 is relatively new and am using it now mostly with my new mini-mill though I am doing some clearing, cutting the firewood to sell next year. Would going to a 40 to 1 have any benefit? Thanks..


----------



## yooper (Mar 2, 2010)

what are you talking about? doesn't the saw get enough oil by putting it in the hole next to the gas hole. heck mine goes through a whole tank of oil almost every time I gas up.


----------



## mtngun (Mar 2, 2010)

SteveG said:


> Would going to a 40 to 1 have any benefit?


Most of us CSM'ers run 40:1 or 32:1 or thereabouts. 

Benefits are hard to prove, hence the never ending debate on the best oil mix.

My take is that 50:1 is largely the result of EPA regulations and that manufacturers would recommend a richer mixture if the law allowed. 

However, modern 2-stroke oils are pretty good and no one will think the less of you if you prefer to run 50:1.


----------



## BobL (Mar 2, 2010)

I use 40:1 for milling, and since milling is my main activity by far I don't like to have different mixes around to go stale so I run 40:1 on all my saws. 

RE:The rationale for 40:1.
I haven't seen any hard scientific testing but it just seems like the right thing to do for a 2 stroke under that much of a load. 50:1 would probably be OK for milling but I'm not taking a chance on it. 

I do have reasons for not going less than 40:1 and that is the excess lube gives me a headache and when milling using a forward facing exhaust saw it turns my chaps black.


----------



## Rob D (Mar 2, 2010)

I use 50:1 and have had no problems so far... But it does niggle at the back of my mind that maybe I should go to 40:1

These days I'm not so much in a rush CSM so let the saw idle along the plank... And just making sure the chain stays sharp. I almost think that is the most important as a dull chain = higher revs = more potential probs IMO.


----------



## SteveG (Mar 2, 2010)

Rob D said:


> I use 50:1 and have had no problems so far... But it does niggle at the back of my mind that maybe I should go to 40:1
> 
> These days I'm not so much in a rush CSM so let the saw idle along the plank... And just making sure the chain stays sharp. I almost think that is the most important as a dull chain = higher revs = more potential probs IMO.



Hey Rob, 

How far are you from Keene? The 5 coldest winters of my life were in NH. I still loving going back to visit (in the warmer months). My wife is from the Boston area and still have a couple of brothers there. Would love to see the White Mountains once again. Beautiful country but way too cold for me.


----------



## Stihlman441 (Mar 2, 2010)

If you use a mix of 40 :1 and a name brand fully synthetic oil and fresk hi octane gas you cant go wrong.


----------



## jimdad07 (Mar 2, 2010)

40:1 seems to me that it would lube the engine a little better, that is why I like to use it. It is a lot harder on the saw to mill. Good synthetic should be what you use no matter if you are milling or not, better for the tree growing.:greenchainsaw:


----------



## splitpost (Mar 3, 2010)

Yep 40:1 mix for all my 2 stroke gear,just to keep it simple:greenchainsaw:


----------



## Sledcrazzy (Mar 3, 2010)

I grew up pushin chain saw mills with 090s on them and we ran 25/1 all the time, one of our mill saws must have over 2000 hours on it and it still runs good.
Oil`s cheap, big saws are not.


----------



## splitpost (Mar 3, 2010)

i to used to run 25:1 as per the stihl shop that sold me the 660 yes its cheap insurance but after awhile i got jack of replacing plugs cause they would foul up after a couple of hours cutting ,maybe those big bangers like it rich dunno?


----------



## tlbsg (Mar 3, 2010)

this post reminds me of my neighbour his saw wouldnt run brought it over for me to try to start he said he did everything right even put 2 stroke oil in fuel tank yes filled the fuel tank with two stroke oil , thats right isn't it?


----------



## SteveG (Mar 3, 2010)

Stihlman441 said:


> If you use a mix of 40 :1 and a name brand fully synthetic oil and fresk hi octane gas you cant go wrong.


 
I've only ever used the oil that Stihl sells. I buy the 5.2 ounce bottle that makes 2 gallons of mix at 50 to 1, their recommendation. Doing the math, I come with 1.6 gallons of gas to get to a 40 to 1 ratio.


----------



## dustytools (Mar 3, 2010)

I too run my saws at 40:1 with synthetic oil. Detuning a milling saw by about 1K is also something that I do for a little added insurance.


----------



## mtngun (Mar 3, 2010)

splitpost said:


> i to used to run 25:1 as per the stihl shop that sold me the 660 yes its cheap insurance but after awhile i got jack of replacing plugs cause they would foul up after a couple of hours cutting ,maybe those big bangers like it rich dunno?


Yeah, we used to run more oil in the old days but changed or cleaned spark plugs frequently, too.


----------



## BlueRider (Mar 3, 2010)

I have been running 50:1 for milling since 1994 with no problems. The rising oil ratios are not a result of the epa but a result of superior tecnology in lubricants. 25:1 or 32:1 were standard ratios back when castor bean oils were the hot product for high performance 2 strokes. Now the high performance guys are all running full synthetic at 50:1. You are free to buy more oil and get less power if you like but my saws are still running strong and I have been milling longer than most around here.


----------



## gemniii (Mar 3, 2010)

tlbsg said:


> this post reminds me of my neighbour his saw wouldnt run brought it over for me to try to start he said he did everything right even put 2 stroke oil in fuel tank yes filled the fuel tank with two stroke oil , thats right isn't it?


No, tell him he's been running it a bit rich. Then confiscate the saw.
I suppose that's easier to fix than one run on straight gas.
Now if it was a high quality sticky bar oil???


----------



## Andrew96 (Mar 4, 2010)

gemniii said:


> Now if it was a high quality sticky bar oil???



My neighbour showed up with some little box store saw that wouldn't start very nicely (green maybe?). After pulling the cover, we found the problem but also I figured out he mixed 'chain saw oil' (which was bar oil) at 50-1 with gas. It ran...two seasons. The air filter was the real problem...simply amazing.


----------



## aggiewoodbutchr (Mar 4, 2010)

BobL said:


> I use 40:1 for milling, and since milling is my main activity by far I don't like to have different mixes around to go stale so I run 40:1 on all my saws.
> 
> RE:The rationale for 40:1.
> I haven't seen any hard scientific testing but it just seems like the right thing to do for a 2 stroke under that much of a load. 50:1 would probably be OK for milling but I'm not taking a chance on it.
> ...



This pretty much covers my opinions.


----------



## CoreyB (Sep 29, 2015)

BlueRider said:


> I have been running 50:1 for milling since 1994 with no problems. The rising oil ratios are not a result of the epa but a result of superior tecnology in lubricants. 25:1 or 32:1 were standard ratios back when castor bean oils were the hot product for high performance 2 strokes. Now the high performance guys are all running full synthetic at 50:1. You are free to buy more oil and get less power if you like but my saws are still running strong and I have been milling longer than most around here.


Instead of starting another oil thread I just have a specific question. 
Would you use a 50:1 on an old saw like a stihl 056? I have an old 056 that spent it's life on 32:1 and want to use it to mill. I also have new saws that have leaner factory suggested ratios. I would like to just use one mix and get the best performance but do not want to risk any of my saws.


----------



## mdavlee (Sep 29, 2015)

I like 32:1. Run whatever makes you feel warm and fuzzy.


----------



## BobL (Sep 29, 2015)

CoreyB said:


> Instead of starting another oil thread I just have a specific question.
> Would you use a 50:1 on an old saw like a stihl 056? I have an old 056 that spent it's life on 32:1 and want to use it to mill. I also have new saws that have leaner factory suggested ratios. I would like to just use one mix and get the best performance but do not want to risk any of my saws.


I would use what the mauufacturer recommends for that saw but make sure it is tuned a little on the rich side.


----------



## CoreyB (Sep 29, 2015)

mdavlee said:


> I like 32:1. Run whatever makes you feel warm and fuzzy.


I have not done any milling yet and can not replace this saw. So I have not found a warm fuzzy ratio yet. 
So are you saying sense it is an older saw that I should use 32:1?


----------



## mesupra (Sep 29, 2015)

IMHO I think good fuel is way more important than the 40:1 / 50:1 debate. I see way more saw issues caused by ethanol than lack of oil. I run 40:1 and use aviation fuel. I would take a day off from cutting before I would put pump fuel in my saws


----------



## mdavlee (Sep 29, 2015)

CoreyB said:


> I have not done any milling yet and can not replace this saw. So I have not found a warm fuzzy ratio yet.
> So are you saying sense it is an older saw that I should use 32:1?


Buy fresh gas and run plenty of oil. I run pump gas all the time but store the saws and all other *** with VP gas now.


----------



## Timberframed (Sep 29, 2015)

I've been reading up on US2 oil. Worth the time to study what the oil actually does under fire.


----------

