40-1 vs. 50-1 ???

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DFK

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Y'all must be slowly working your way into my head.
Ever since I found this site I think "Chainsaw" half the time.

Having read quite a bit on this site I see that a lot of you run a 40-1 mix in saws that the maunfactors of the saws reccomend that a 50-1 mix be run in.

If I understand it right this richer mix protects the saw better from wear. That makes since.

Would it be worth my effore to run a 40-1 mix in my two year old Stihl MS310?
Will I have to tune the saw or anything else to run a 40-1 mix?

David
 
It's not necessarily needed. I only run more oil because most of my saws are ported. Most important is to run a full synthetic oil.

Yes I believe with Synthetic you can run more oil, because it burns better than conventional 2 Stroke oil. If your saw is smoking all the time, it will build up carbon in the exhaust section, which is not good for the saw. With synthetic you get less smoke and less carbon build up.
 
Quite the opposite... synthetic oil lubricates better and that is why the requirement for less oil is implied.

50:1 mix with full synthetic 2 stroke oil will lubricate any saw known to mankind. No matter how old or new they are. Or even if they are ported...

Gary
 
Supposedly ported saws run cooler, and since they move a greater volume of fuel mix through the cylinder, with a lesser proportion of it burned, why would they need more oil? Just curious.

More generally, the difference between 40:1 and 50:1 is much smaller than the difference between a saw that is properly tuned and one that is a bit too lean. Another point is that with more oil in the mix, there is less gas, meaning less octane. The fuel mix also cools the saw when the more volatile components vaporize inside the crankcase, so more oil in the mix means less evaporation and less cooling. So optimally one would run the highest ratio of fuel:eek:il that still provides sufficient lubrication. How to determine this optimal ratio? Lots of expensive empiricle testing of the sort done by engineers at the major chainsaw manufacturers. Those engineers say 50:1.

Some say that it was the Iron Fist of the EPA that forced the engineers to use 50:1, but there's little evidence to support that claim. Take something like mufflers which engineers actually were forced to use to control emissions. We can open up the muffler and see significant gains, especially on the saws made right after emissions standards were ramped up. But what difference do we see going from 50:1 to 40:1 or even 32:1? None. Saw techs aren't reporting a scourge of failed bearings or rods on saws running 50:1 instead of 40:1. Instead, there are LOTS of users running 50:1 in saws that hold up to punishment as well as saws from any era. As a sort of control, quick Google search finds reports of early wear or failure in saws running 100:1 snake oil, which suggests that 50:1 really is optimal for modern saws and lubricants.
 
You're going to get all sorts of opinions on the matter.

End of the day, as long as you're using quality mix and not letting it sit around for ages, I think you're fine with either 40 or 50 to 1. I personally use 40 to 1 in everything simply because its easier to remember for all of my saws and equipment, and its one of those cases where its just "worked for me" always.


Will I have to tune the saw or anything else to run a 40-1 mix?

You most definitely should tune your saw if you change to a 40 to 1 mix. Heck, even maintaining a mix rate and changing brands of gas or oil, I tend to look at retuning. Often its not more than 1/8th of a turn - and sometimes its no turns at all - but its certainly worth looking at if/when you switch.
 
I have heard the opposite

Supposedly ported saws run cooler, and since they move a greater volume of fuel mix through the cylinder, with a lesser proportion of it burned, why would they need more oil? Just curious.

More generally, the difference between 40:1 and 50:1 is much smaller than the difference between a saw that is properly tuned and one that is a bit too lean. Another point is that with more oil in the mix, there is less gas, meaning less octane. The fuel mix also cools the saw when the more volatile components vaporize inside the crankcase, so more oil in the mix means less evaporation and less cooling. So optimally one would run the highest ratio of fuel:eek:il that still provides sufficient lubrication. How to determine this optimal ratio? Lots of expensive empiricle testing of the sort done by engineers at the major chainsaw manufacturers. Those engineers say 50:1.

Some say that it was the Iron Fist of the EPA that forced the engineers to use 50:1, but there's little evidence to support that claim. Take something like mufflers which engineers actually were forced to use to control emissions. We can open up the muffler and see significant gains, especially on the saws made right after emissions standards were ramped up. But what difference do we see going from 50:1 to 40:1 or even 32:1? None. Saw techs aren't reporting a scourge of failed bearings or rods on saws running 50:1 instead of 40:1. Instead, there are LOTS of users running 50:1 in saws that hold up to punishment as well as saws from any era. As a sort of control, quick Google search finds reports of early wear or failure in saws running 100:1 snake oil, which suggests that 50:1 really is optimal for modern saws and lubricants.

I only have two saw shops local to me, dealers, and an old guy with a small engine shop close by. All of them have told me they tried to recommend 50 to 1 but have since switched back to 40 to 1. Now their words, paraphrased, they just don't like to see real dry pistons, they want to see oil on them things when they tear them down. So who knows..the husky wrench flat out told me he likes the poulan at 40 to one, over the husky synblend at 50 to 1.

Me, on the fence, I have tried both, I seem to prefer actually around 45 to 1 or so. 40 I see smoke, 50 seems to make things run not so great, they run fast, but seems excessive and sorta hot (which I know is contrary to the chemistry..and I don't know why). So I either mix 50 to 1 and add a small splash more of oil, or 40 to one and a little extra gasoline. (depends on what is left in the oil bottle/ mix jug mostly, and how old the mix is)

As for brands, again, jumped around, I like the echo synblend, but I do NOT like their bottles, some of the good stuff, the sticky stuff, gets stuck down in the bottom and doesn't make it out the squeeze thingee for measuring at the top.
 
i am running 50-1 stihl ultra with 93 octane and there is plenty of oil on the piston when i pulled the muffler:msp_rolleyes:
 
i run everything at 45:1

Yup..or 43:1 or 44:1 or 41:1 or 50:1 or 42:1...or, well, you get the idea. :msp_biggrin:

Too many guys over-think the oil thing. Use a good synthetic, keep your fuel clean and fresh, and it doesn't really matter a few drops of oil one way or the other.
 
Man. Recommendation

I run 50:1 with name brand oil in my modern saws. Metallurgical and technological advances allow improvement, but I run what's recommended. When I worked in the saw shop, it seemed that the saws being run with more oil exhibited excessive carbon build up throughout. Fun facts: my 1958 model 7-21 gear drive Homelite calls for 3/4 of a pint 30w per gallon... works out to 10.67:1 ;) my olive drab 1968 Remington Arms Co. saw calls for 16:1
 
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I agree with several people on here, quality synthetic oil, in my case Stihl Ultra and 93 octane NO ETHANOL, and TUNED PROPERLY! I was told by Dave Neiger that the more oil you run the lower the octane of the fuel, he said 50:1 in anything 2-stroke, even my old Pro-mac 700 runs alot better on 50:1 versus whatever the factory calls for! I think what I all capped is the biggest things to chainsaw longevity, IMHO!
 
Ive had good luck over the years with 40:1. Ive always used dino up until a year ago, and switched to HP. Everything is looking good so far! Im a bit concernced over the fuel, but have been using 93 with ethanol without any problems.
 
One of the largest Stihl dealers I've spoken to said that most loggers in his area were running 50:1 in their 660 Stihls for years. This dealer found that internal wear was worse than the guys running richer oil ratios (down to 25:1) when saws were pulled down a few years later. Once this was realised basically all pro users in the area started running 25-30:1 in their 660's. Whether this even works out to be economically viable over the life of a saw I'm unsure. This dealership used to shift about 60 x 660's to loggers a season and serviced basically all of them. They should know what they're talking about.
It pays to remember that most of us here will never run a saw for enough hours to see any difference in wear between higher or lower oil ratios. It's easy to say that a saw looks great internally after 100-200 hours when pulled down but how many of us get the chance to compare two saws side by side with 1500 hours on each, both having run different oil mixes?
It's like saying that Stihl RSC is the best wearing chain on the market after only one cut.
Just putting that out there...

Quite the opposite... synthetic oil lubricates better and that is why the requirement for less oil is implied.

50:1 mix with full synthetic 2 stroke oil will lubricate any saw known to mankind. No matter how old or new they are. Or even if they are ported...

Gary

Hi Gary.
Can you explain to me why in my Aussie delivered 3120 Husqvarna manual they recommend 25:1? If I ran a leaner oil mix than that in my 3120 (when it was under warranty) and there was a problem my warranty would have been null and void. This is an 08 build saw.
I really want to know why the manufacturers specify more oil in their larger saws yet people don't think it's needed? I realise that the oil ratio is consistent with the amount of fuel they use so a larger saw using more fuel doesn't necessarily need more oil.
Not being a smart arse it's just that I think the manufacturers may know something that we seem to be ignoring. I've posed this question before and would love to hear the manufacturer's reason behind their 25:1 recommendation.

I run 40:1 in all my saws except my 3120 that I run 30:1 in.
 
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Lol! I'm not too worried about say an MS250 or wild thingy on 50:1. But don't try to tell me to run an $084 or $3120 on 50:1 when they're expected to run a mill or a 60 inch bar cause it aint gonna happen.:laugh:
 
So if I switch to a synthetic I can cover a broader range. If I have machines which run 32:1, 40:1 & 50:1 then I can go to one mixture? What mixture should I run and what are considered good brands?
 
I run 50:1 Husqvarna oil in all my saws starting 13 years ago. No problems. Every once in awhile I'll run Stihl Ultra at 50:1.
I'm not saying 50:1 is the perfect ratio, but til I have oil related problems thats what I'll run.
I believe whats more important is to tune the saw to the mix you pick.:popcorn:
 
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