40-1 vs. 50-1 ???

[one.man.band]

just lost 10 minutes of slow typing somehow, hate it when that happens!

50:1 is what manufacturer recommends for my saw. Works for me. Starts up after a few pulls, idles well, plug color fine, changed plug once in the last 5 years (didn't need to, but did anyway), cuts wood. See no reason to change.

Folks here run everything from 16:1 to 100:1. Those folks who run at the extreme limits know how to tune their saws, and have good results, and see no reason to change.

Folks who soup up saws have had their fingers in hundreds/thousands of saws, know what ratios their saws like, and most definitely know how to tune, no question. Folks who own those types of saws are experienced tuners as well. They want the most out of their saws, and tune accordingly.

50:1 is 2% oil/gas mix. For every 1% change, it roughly equates to about 1 jet size. Most 2 stroke carbs have jets that come in 1% size increments that i have come across anyway. Saws however, have adjustment screws. Suggest small tuning adjustments are necessary if increasing oil ratio to 2.5% or decreasing to 1.5%. Will the saw blow up if you don't retune? Probably not. Will it run better after retuning? Certainly. For a 1% change or more either way, it would be necessary to re-tune properly IMO to avoid potential engine problems.

Changing ratios without retuning is not the best idea. There is great tuning advice threads found elsewhere on this site from folks who definitely know their stuff. Mix ratio charts are available as well.

 

[Alan Farms Jr]

As a small engine mechanic I'll say this. "Non-ethanol" gas is the most important thing to use. Using 40-1 or even 25-1 is recommended. The oil lubricants do a much better job w/non-ethanol gas. Period. We small engine mechanics see 80% plus, of our work, due to ethanol gas. It's horrible for all small engines, especially the carburetors. The pistons and rings wear more aggressively, due to ethanol. Yes, the EPA and the oil companies know this, but not the average "Joe." In Europe and Asia the recommended fuel mix is 25-1 in all 2 cycle small engines! Happy Trails!

 

[7sleeper]

Sorry my friend but this is NOT true. Recommended mix ratio here is in Europe has been 1:50 for at least a quater of the century.

And over here in german speaking forums we DON'T have small engine mechanics complaining about 80% plus due to ethanol gas. And yes there have been more problems since the changeover to higher ethanol content, but never in the dimensions you describe. Further there isn't any scientific proof for more aggressiv piston or ring wear that I am aware of.
And yes 10% ethanol has been on the market for at least a decade and before that there has been 5% ethanol content.

And as I have mentioned here already countless times, the fuel providers or oil companies are NOT to blame here. They are simply doing what the law tells them to for many years. The real problem are the manufacturers of two/four stroke equipement who are simply not reacting accordingly and producing the right equipement resistant to ethanol in the fuel!

7

 

[wde_1978]

I aim at 50:1 for my chainsaws, and 40:1 for my weed eaters.
The actual percentage tends to be a tad richer as I usually pull a bit more oil into the measuring syringe just to be on the safe side.

Switching between 50:1 and 40:1 on my saws doesn't seem to make any noticeable difference in behavior or power output.
On the other hand switching between different oils can make a huge difference.
I like Dolmar and Makita 2 stroke oil.
I have tried "INA" (Croatian manufacturer), Ratioparts and Divinol - I guess it works OK, but I didn't like it for my chainsaws once I discovered and got used to the Dolmar oil.
Divinol 2 stroke oil at 40:1 leaves a ceramic like glazing on the muffler outlet and smokes quite a lot. I stopped using it in my chainsaws mainly because of the glazing, but will spend the remaining stash on my weed eaters as they are much more affordable to replace if something goes wrong after all (1.5kW generic supermarket weed eater with 3 years warranty ~100$).

We (my dad and I) tried running an 1960's Sachs Stamo 96 2 stroke engine mower at 25:1 using nowadays 2 stroke oil. It smoked extremely and within the first tank of fuel the engine started choking on excessive unburnt oil. We reduced the mix to 40:1 and the engine handles it much better.

Thus far I used only non-E pump fuel, leaded while it was available, unleaded nowadays.

My 1980's Sachs-Dolmar 105 is sporting all her factory original rubber pars and carb kit - KNOCK ON WOOD!

 

[Alan Farms Jr]

Let me make it clear. Ethanol is a solvent. It attracts a lot of moisture(H2O) over a short period of time. It then becomes very acidic. This eats away at the carbs as well as the internal combustion chamber. The plastics and rubber then get hard and even brittle. Too much water in the gas can cause catastrophic damage. Check out www.youtube.com and the video's on ethanol gas and it's hazardous properties. Look, I'm just a small engine mechanic. I love ethanol gas for one reason only; I make a "sh*t load." of money because of it. "Take it or leave it". Happy Trails!

 

[blsnelling]

IMHO E10 is not a problem at all unless it's allowed to get stale or improperly stored and moisture get in it. Keep your fuel less than 6 months old and I doubt you'll have any issues, other than accelerated fuel line/carb diaphragm deterioration. But, as far as running goes, it's a non-issue, IMHO.

 

[bwalker]

This thread has so many old wives tails and bad info in it that it should be taken down.

 

[weimedog]

Speaking of dirt biking, does anyone use the high quality dirt bike synthetic oil? Specifically maxima castor 927 (castor oil) ?

32:1 with Bel-Ray H1R for saws and dirt bikes....or simply 32:1 with Husqvarna Branded synthetic when I don't see Bel-Ray on the shelf. There are several really good motorcycle targeted oils out there. Over kill? Maybe. But the more I see especially of the newer strato saws with all that raw air carried by the piston has kept me in the "if it ain't broke don't fix" it modus opperendi with 32:1. One thing is the typical saw enthusiast here has multiple saws and will rarely run them enough to even tell a difference say between 32:1 and 40:1. I do see more than a few repair jobs from the commercial types. All I can say it anything to push statistics in the direction of more reliability is a good idea...

 

[rwoods]

As I posted in the latest fuel thread, I can't believe that in one morning I have actually read a fuel thread and an oil thread as I usually don't read either much less post in them as all I know about fuel and oil is anecdotal.

FWIW, the manufacturer's recommendations for my two strokes range from 32/1 to 50/1 with many of mine at 40/1. I used to mix all three. Now I just mix two. 40/1 and 32/1. 40/1 goes in everything except my saws with a manufacturer's recommendation of 32/1 and my one ported saw. Zero issues. Overkill maybe.

Ron

 

[Little Al]

In Europe and Asia the recommended fuel mix is 25-1 in all 2 cycle small engines! Happy Trails![/QUOTE]
Where did you obtain that info from? the big 2 recommend 2%with their own oil which =50/1 & 3 to 4% if you use other brands of oil. Efco are 2% ers as well.All the modern hedge trimmers Blowers etc are 2% With Quality oil.The saws that are produced in Europe are in a lot of cases exported to the US so why would the mix ratio differ, the only difference we have were I live is ALL of our fuel is E free.

 

[HuskyHeadDave]

Sorry my friend but this is NOT true. Recommended mix ratio here is in Europe has been 1:50 for at least a quater of the century.

And over here in german speaking forums we DON'T have small engine mechanics complaining about 80% plus due to ethanol gas. And yes there have been more problems since the changeover to higher ethanol content, but never in the dimensions you describe. Further there isn't any scientific proof for more aggressiv piston or ring wear that I am aware of.
And yes 10% ethanol has been on the market for at least a decade and before that there has been 5% ethanol content.

And as I have mentioned here already countless times, the fuel providers or oil companies are NOT to blame here. They are simply doing what the law tells them to for many years. The real problem are the manufacturers of two/four stroke equipement who are simply not reacting accordingly and producing the right equipement resistant to ethanol in the fuel!

7

Wrong.... Start building saws and tearing them down multiple times a year and you'll see the film on internal parts...colors...carbon...all internal parts period. 32 is great...40 is what I run because it's tuned rich and 50 with the addition of moonshine and the water it collects breaks the film in the cylinder...on the cylinder walls and the piston skirt. It's streatched to its max and then with the addition of a slightly lean condition or minor air leak from eaten rubber fuel or intake lean condition you have catistrofic failure. At 32 you hear higher RPM's and feel a power boost and should immediately realize you have an issue... The internals survive to run another day!

 

[7sleeper]

Sorry but irrespective of 1:32, 1:40 or 1:50, if you don't hear your saw is running wrong because of an air leak, there is nothing in the world that is going to save your saw. Not more oil or rich tuned carb, nothing!

And I don't want to tear down saws multiple times a year, because if you have to do that to your saw something is wrong anyhow. And for me saws are a tool, and they are used and not cradled to sleep. If I look at what the pro's do here, they have absolutely NO problem with running the saws for years on end at 1:50. And miraculously as most pros, they only have to exchange them after 2-4 years. But you can feel free to come over and tell they are stupid because they are doing this.

Then again one has to wonder why the chainsaw companies are recomending 1:50 for ALL their two stroke epuipement even in countries where NO EPA exists....

Further nobody actually knows if a saw engine will run for ever if you increase oil to 1:32 but to be honest no one wants the saw after 4-5 years pro use, because a lot of other things are already getting "loose".

7

 

[CR888]

50:1=2% oil in fuel mix, 40:1=2.5% oil in fuel mix. Does anyone realise how many thousands of pages of gozzoble have been written about this minute fact. Wish I could say its funny but...

 

[bmwpowere36m3]

I'd venture to say there's more variability in mix ratio simply due to human error... how may users are actually metering out the required fuel quantity or simply relying on the marks on the side of the can or eyeballing it. When a manufacturer states 50:1, you can bet there's already a safety factor built-in.

Oil technology moves forward, just like days past of 3k motor oil changes. In days past equipment needed 25:1, 32:1 because that was the capability of oil at the time. I read a paper regarding oil Amsoil tested and it was able to run at 300:1. However they knew, there was no way to sell it... or convince consumers.

That said, there was also a paper regarding power vs. mix ratio... it concluded that more oil (to a degree) was better for power (needed to be tuned as well). Everyone likes to think their saws are precious and their using them in "extreme" circumstances. Certainly there are applications that can warrant slightly lower mix ratio (more oil). Personally I stick to 50:1 in everything using high quality semi/syn oil. If I get a chance to run Amsoil Saber, I'll going to jump to 80:1 without worries.

I mix 1 gal at a time, so when you get to the really high mix ratios, the error in measurement for oil gets too high (for me).

 

[Hoolio]

32-1. Stihl ultra hp. With 98ron. Don't know that much about fuel but I figure the octane levels drop over time? So it should last longer? It's non ethanol and apparently burns cleaner in a four cycle car engines.
Also being 32:1 if for example if someone used the wipper snipper and topped it up with straight fuel it could still be around 50-1 and should run slightly richer. I think that's how it works?

 

[weimedog]

I'd venture to say there's more variability in mix ratio simply due to human error... how may users are actually metering out the required fuel quantity or simply relying on the marks on the side of the can or eyeballing it. When a manufacturer states 50:1, you can bet there's already a safety factor built-in.

Oil technology moves forward, just like days past of 3k motor oil changes. In days past equipment needed 25:1, 32:1 because that was the capability of oil at the time. I read a paper regarding oil Amsoil tested and it was able to run at 300:1. However they knew, there was no way to sell it... or convince consumers.

That said, there was also a paper regarding power vs. mix ratio... it concluded that more oil (to a degree) was better for power (needed to be tuned as well). Everyone likes to think their saws are precious and their using them in "extreme" circumstances. Certainly there are applications that can warrant slightly lower mix ratio (more oil). Personally I stick to 50:1 in everything using high quality semi/syn oil. If I get a chance to run Amsoil Saber, I'll going to jump to 80:1 without worries.

I mix 1 gal at a time, so when you get to the really high mix ratios, the error in measurement for oil gets too high (for me).

I am hoping you really test the theory and report. Especially the 300:1 Someone has to put their money where their mouth is. So much speculation based on what someone ELSE has said or written. Some extrapolated from pure marketing presentations. Others from experts who rarely crack a set of cases to see the results of other users habits. Being an old man from the stone age with glasses, I happen to measure with one of those "Ratio Right" Measuring cups at 32:1, with Husqvarna Synthetic or Bel-Ray. Maybe with your testing you could save me a pile of money using a lot less oil.. or maybe someone else will be enlightened to the modern ways of petroleum chemistry. If nothing else it would be a good read & possible a fun YouTube Video. But for now, until I see reasons to change....sticking with 32:1... I have an open mind...just I like Empirical Data that I can see vs. speculation. Unfortunately to this point in time the most significant advances I've seen this last 15 years or so have been in the marketing and packaging from what I can tell. I for one would love to see some changes! SO...if they are out there .. let it RIP!

(I've seen more than a few reasons to STAY with what I do this past three years! )

 

[bmwpowere36m3]

I am hoping you really test the theory and report. Especially the 300:1 Someone has to put their money where their mouth is. So much speculation based on what someone ELSE has said or written. Some extrapolated from pure marketing presentations. Others from experts who rarely crack a set of cases to see the results of other users habits. Being an old man from the stone age with glasses, I happen to measure with one of those "Ratio Right" Measuring cups at 32:1, with Husqvarna Synthetic or Bel-Ray. Maybe with your testing you could save me a pile of money using a lot less oil.. or maybe someone else will be enlightened to the modern ways of petroleum chemistry. If nothing else it would be a good read & possible a fun YouTube Video. But for now, until I see reasons to change....sticking with 32:1... I have an open mind...just I like Empirical Data that I can see vs. speculation. Unfortunately to this point in time the most significant advances I've seen this last 15 years or so have been in the marketing and packaging from what I can tell. I for one would love to see some changes! SO...if they are out there .. let it RIP!

(I've seen more than a few reasons to STAY with what I do this past three years! )

Did I recommend running 300:1? Amsoil will only warranty/guarantee Saber Pro against any damage caused the oil when used at 80 to 100:1. Use whatever makes you feel comfortable. We deal with people that still can't accept oil changes past 3k in our business... I also noted running that high of mix is not necessarily good for power. Depending on equipment and use, low mix ratios can lead to excess carbon build up, lose in power and excessive smoke/emissions.

If your saying there's a difference between 40 to 50:1, then I'll say you've probably run that range unknowingly.

At 300:1... you'd better be measuring very accurately. Is it going to save you any money? Depends on how much mix you go thru. Is it worth the risk? Again, depends. We've been running 50:1 in all our Stihl and Echo equipment for the last 20 yrs without issue. That's my experience...

AND

Oil, fuel, ethanol and mix discussions are like religion.... for the most part, people are stuck in their ways and people have very strong beliefs.

 

[bmwpowere36m3]

More importantly is having a properly tuned saw... do more damage in my opinion than the mix ratios were talking about.

 

[weimedog]

I also noted running that high of mix is not necessarily good for power. Depending on equipment and use, low mix ratios can lead to excess carbon build up, lose in power and excessive smoke/emissions.

.

And religion is about belief in something more than a "believer' can understand...so they have to have faith... Good analogy I think.. So just out of curiosity. WHAT has more BTU's per unit volume. Oil or Gasoline? And based on the understanding of that, what has more energy per pop, 80:1 or 32:1? Is oil a fuel and contributing to power or something less and reduces the amount of energy released? Like I said, just an old man and can always learn. And a question for the History buffs Caster Bean Oil..is it still on the market and if so why? Last but least to the motorcycle guys, remember the old Bel-Ray MC1? They came out with H1R and that was a huge advance Pretty much had to run the MC-1 at 50:1.....not so with the H1r. I think the first two stroke I had to rebuild was in 1971, and it was an old 1970 Bultaco Sherpa S 200. That is a confession or admission depending on your perspective.

I also think the definition of "no trouble" is hard to quantify in discussions like this as there are so many different service conditions. There are a lot of two strokes running 50:1 and lasting their intended service life, and why for so many years it has been recommended...along with the advent of the newer generation synthetics and just good quality oil. AND its easy to point to user error when things in fact fail. Cylinder packed with crud, dull chains...etc.The real question is what does that mean? Does mixtures like 32:1 meet that standard as well? And which do better in special cases that push the boundaries of the properties of those oils? Especially with these new Strato saws retaining more heat in the system and also washing a whole section of the top end with raw air. Is 50:1 a better choice than say 40:1 or even 32:1? Does it even matter? Curious as to your thoughts.

 

[bmwpowere36m3]

I'm far from an expert, but my educated guess would be 2-stroke oil has more [BTUs]... however all the tests/reports seem to attribute the increase in HP to better ring seal and thus higher compression. I would also believe more oil would increase the octane of gasoline (i.e., harder to ignite oil than fuel), but that's likely insignificant.

Castor bean oil is still sold, like Maxima 927. Some old timers and racers swear by it. My understanding is it had/has some better lubrication properties, but they come at a cost... separation from fuel and deposit control. Now how does it compare to today's semi-synthetic and synthetic oils from a lubrication stand-point.... I don't know. Newer oils defiantly have better deposit control and less likely to separate.