Why 50:1 is the Best Ratio

[KenJax Tree]

I am too.

Hey, if the shoe fits....[emoji2]

 

[Rx7man]

I'm running my piped saw at 24:1, ported saws at 32:1, and the weedwackers, etc at 40:1. I expect to have a little smoke if it's idling, and expect to have it clear up under load. I'm really not hung up on oil ratios, I just make sure it's got enough. If all I have is 40:1 and I need to fuel up the 'hot saw' I will dump a capfull or two of bar oil in it. It's survived getting overheated twice now with no scuffing.

Changing from 50:1 (2%) to 32:1 (~3%) is a 50% increase in lubrication.. I'm not terribly concerned about carbon buildup, the saws come apart once in a while anyhow just to see how they're doing.

 

[wde_1978]

I used to run any oil at hand at 25:1 in my lil old Sachs-Dolmar 105, even plain engine oil.
I remember lots of smoke, no mechanical issues though.

Since 2006. I run Dolmar oil at 50:1 in my saws, my PS-6400 still ended up having carbon related scoring so I guess it is not only the oil that will cause deposits.

Ran out of Dolmar oil this year, used briefly other oil (Divinol) at 40:1 - terrible.
Extreme smoke cloud while bucking and a very suspicious looking black "glazing" on the exhaust hole.
I am now back to Dolmar (Makita) oil at 50:1 - no smoke under load, and no "glazing" on the exhaust port of the muffler.
That other oil will be spent on my cheap supermarket weedwhacker, if it craps out so be it.

Since 2006. my old SD105 gets Dolmar oil at 50:1 and I dare to think she likes it.

 

[procarbine2k1]

An 026 I took in for repairs had a few issues, but was used for 10 years and ran only on 40:1. The spark arrestor was plugged with carbon, a cylinder bolt was missing and the carb had never been adjusted.
My point is, most saw owners should run 50:1 because they never touch the carb, which most of the time is set too rich.
I fixed the 026, and perforated the muffler and told him his brand new 261 will take a back seat.
Why go fatter when the saw is already fat?

Agreed. I had an 026 that I was running 40:1, and had the rear handle crack on me. I replaced the rear handle and went back to 50:1, with no more problems.

I hate to ask, but how many cylinder bolts does an 026 have? Mine came with 3 and I remember buying it new from Walmart, where most Stihls should be purchased.

 

[fossil]

Agreed. I had an 026 that I was running 40:1, and had the rear handle crack on me. I replaced the rear handle and went back to 50:1, with no more problems.

I hate to ask, but how many cylinder bolts does an 026 have? Mine came with 3 and I remember buying it new from Walmart, where most Stihls should be purchased.

That depends. If you just buck with it, likely four. If you fell, maybe two. If you try to cut upside down, one or none.

 

[weimedog]

still 32:1 after all these years...

 

[Rx7man]

still 32:1 after all these years...

I don't think you can go far wrong with that!

 

[Adirondackstihl]

the thing about motul is no smell but it lacks decent fuel dye but does have dye in it.

Have you ever held a bottle of the stuff? Or run it in your OPE?

Smells nice and racey and has a bright red dye.

 

[BuckMKII]

Motul 710 had a very faint green dye. I'd prefer it darker.

 

[scallywag]

Smells nice and racey and has a bright red dye.

Our 98 octane is purple, no mistaking it once its mixed, it is indeed bright red, looks like the old 'super grade' fuel we had back in the 70's.

 

[KenJax Tree]

Have you ever held a bottle of the stuff? Or run it in your OPE?

Smells nice and racey and has a bright red dye.

See my lawn jockey comment is making sense[emoji23]

 

[Deleted member 83629]

Hey, if the shoe fits....

sometimes it fits. i got to take down a black walnut tree today because im tired of getting pelted by walnuts.
so i will report back if 50:1 kills my saws.

Have you ever held a bottle of the stuff? Or run it in your OPE?

Smells nice and racey and has a bright red dye.

yes i have anything else?

 

[Deets066]

I mixed up some of the mythical
Mobil 1. 2t today at 32:1, I haven't ran any of it yet but kinda wish it had some dye in it

 

[Artemis]

there is no best ratio. 50:1 is just the most popular. 2 strokes are usually very forgiving. you can run quite a range of mixes and be totally fine. Ive even heard of people running 2 tanks of straight gas through before they noticed! Must've had a lot of residual oil in the crankcase eh? Also the quality of oil makes a huge difference. That cheap crap carbons up a lot sooner than higher quality oils like Amsoil or Lucas. I prefer semi or fully synthetic oil and I mix 37:1 for the 372, and 40:1 for the 445. When I pulled the cylinder off my yamaha yz250 dirt bike there wasnt a hint of carbon or scoring on the piston. I used only Amsoil Dominator in that bike and I will be switching from lucas to amsoil for the saws as well once this bottle runs out. The oil really does make a difference.

 

[MountainHigh]

Please pay attention ...
For the best Oil to Gasoline ratio, the formula is always [Barometric Pressure] minus [ambient temperature] divided by the number of hours you've used the saw at full throttle (refer to your log book) . . . .

Try to keep up - there will be a test!

excerpt from . . .
National Lubrication Council (NLC)
Standards and Practices Division


(please note, the NLC is in no way affiliated with the GLC/Gynecological Lubrication Council)

 

[chipper1]

I've been running my equipment at 1:1/10.
I use 1 gallon of gas and 1/10 of a 10 gallon bottle of premix.
Should I try 1:.5/10
And when is this test, I feel I'm having a difficult time keeping up

 

[SEAM]

There is another thing no one has mentioned. The raw 2-cycle oil gets pre-diluted to a standard ratio. This dilution ratio determines the fuel-mix ratio.
There are oils for 20:1, 33:1, 40:1, 50:1, 100:1... the higher the number, the more oil content per 2-stroke oil volume, the less oil out of the bottle into the fuel...

I usually go with the ratio recommended for the oil plus a safety margin if necessary for a specific engine type or purpose.
A 20:1 oil mixed at 33:1 would be too little oil, a 50:1 oil mixed at 33:1 would be too much.
Another important spec of the oil is its rating: FB, FC, FD, etc.

 

[Rx7man]

Please pay attention ...
For the best Oil to Gasoline ratio, the formula is always [Barometric Pressure] minus [ambient temperature] divided by the number of hours you've used the saw at full throttle (refer to your log book) . . . .

Try to keep up - there will be a test!

excerpt from . . .
National Lubrication Council (NLC)
Standards and Practices Division


(please note, the NLC is in no way affiliated with the GLC/Gynecological Lubrication Council)

Most people would get a divide-by-zero error

 

[Gypo Logger]

Since moving back to 50:1, I have noticed my saws are self healing and self repairing. Cracked handles and missing bolts are now a thing of the past.

 

[chipper1]

Since moving back to 50:1, I have noticed my saws are self healing and self repairing. Cracked handles and missing bolts are now a thing of the past.

Agreed. I had an 026 that I was running 40:1, and had the rear handle crack on me. I replaced the rear handle and went back to 50:1, with no more problems.

I hate to ask, but how many cylinder bolts does an 026 have? Mine came with 3 and I remember buying it new from Walmart, where most Stihls should be purchased.

Now it's fact, I read it on the internet twice, 50:1 fixes broken handles.
Has anyone else lost bolts while running 50:1, I just want to know the facts.
50:1 must have the same stuff in it as the head gasket repair kit I use .

Local saw shop told me theres a new product coming out called crackout. It works just like whiteout. You just spread it over the crack with a little brush and the crack is gone. The great thing about this product is it works with any ratio you run