Gas/ / Oil Mixture Rate Preference .

[Sodo]

What is the recommended mixture? If recommended is 32:1 then 30 is probably OK. If the jetting screws were set for 50:1 and you're running 30:1 then it's getting less gas and is likely to run lean, = hot, (and seize). In any case, if it was running hot, the mixture screws need to be set for optimum power then a tad rich.

Sorry about the scoring, it might heal. What does the sparkplug look like, any white on it?

How long is each cut? If it can go down to idle after a minute or so (after cutting thru each log) that's enough, you don't have to shut it off.

Probably ought to start a new thread, one specific chainsaw problem is off topic.

 

[Whatswrong]

Thanks Sodo , will mix 40-1 I thought oily would automatically be better ,not understanding jetting settings .

 

[sd455dan]

More oil = less gas, consequently 32:1 needs to be a little richer on the mixture screws. Oil is not a combustible component, if theres too much its getting in the way.

that I am in total agreement with- The fuel mix is also more viscous when more oil is added- which actually makes the engine run leaner- but with more lubrication. As long as the mixture is adjusted -jetting is correct then i think it is fine, I run my saws and string trimmer at 45 to 1 I have a 1954 Johnson Sea Horse that calls for 16 to 1 ( 30 wt engine oil!) I run that at around 36 to 1 outboard oil and had to adjust the jetting leaner.

The one other thing that I do disagree with is the statement that oil (types) make little difference - is when someone uses ANY 2 stroke outboard oil in ANY air cooled 2 stroke engine... the air cooled engine will invariably overheat and in most cases a bunch of compression goes away to if not also scoring the piston /cylinder wall or siezing. Just my :2cents:

 

[TomSeller]

I run mid grade ethanol free gas mixed with Sthl Ultra at the recommended 50:1. I always do this type of thing by the book. I do this with all 5 Stihls and one Homelite 2 stroke engines. No engine issues whatsoever.

Having said that, thank you for starting this discussion. I don't recall seeing this brought up before, but I don't get to the arborist forums enough

 

[PhysAssist]

I run mid grade ethanol free gas mixed with Sthl Ultra at the recommended 50:1. I always do this type of thing by the book. I do this with all 5 Stihls and one Homelite 2 stroke engines. No engine issues whatsoever.

Having said that, thank you for starting this discussion. I don't recall seeing this brought up before, but I don't get to the arborist forums enough

What he said, but while I try to do the same, invariably, I think I probably overshoot just a litte with the oil, agreeing with the premise that a slightly smoky, possibly lightly fouling mixture beat seizing and burning up. I use the same gas I put in my car, but add a measured amount of either stabil or more recently? Optilube or Optiron?

Thanks,
Thomas

 

[FredH]

Harry V : Your Likely right , it is a Oregon Thing !! :thumbsup:

/Pine : Was Not Bashing You by any means , You raise very valid points , Especially your reference to loaning equipment :thumbsup: Rarely loan anything to anybody except my brother , Who is likely better than me at upkeep on tools .

The 2 old 041's that I had were always ran on 32:1 and replaced the intake gasket on oldest one before selling . The piston skirt looked new without any discoloration any were.
Yet my neighbor who bought a new 290 and it seized shortly after 1 year of purchase and maybe 20 hours of use . Used the Stihl oil bottles with a 1 gallon container of gas . This was several years ago ( maybe 5 years ?? ) when this area first started using the ethanol fuel BUT only in the winter months so could that had anything to do with it ??? Could be also that he did something else ????

Plugs in my 041's were not white rather they ended up being more oil fowled by end of year after cutting for 30 hours or so with each saw . Have ran new 441 for 15 or so hours and the plug is looking like the old plugs also after that amount of time . I never used a gas stabilizer , Never Thought of asking that Question , DUH !! :ashamed:. I only mix 1 gallon at a time though and run it in saw , 2 different weed eaters and a gas blower , so it does not sit around for very long .

Again , Sorry /Pine , Did Not mean for my second post to sound like a dig or other , I view the manufacturer's manual's as Recommendation's not something set it stone .

Fred H.

 

[Giles]

Using more oil then recommended by the manufacturer is---in my opinion---a waste! One has to realize that todays oil is MUCH better then what was available years ago. I have used 50-1 ratio in my 1980 model Craftsman saw for years--with no problems!
Some people still change their engine oil every 3,000 miles--to me---that's a waste also.

 

[FredH]

32-1 = 3% oil While 50-1 = 2% oil . One ( 1 ) Percent difference .




Fred H.

 

[sd455dan]

32-1 = 3% oil While 50-1 = 2% oil . One ( 1 ) Percent difference .

View attachment 347280


Fred H.

Not in smoke output :laughing:

 

[Bluegill2]

32-1 = 3% oil While 50-1 = 2% oil . One ( 1 ) Percent difference .

View attachment 347280


Fred H.

Fred, that's a dang good way to look at it!

Guys, a tiny bit more oil wont hurt and can help...