mixing ratios for 2 stroke chainsaws

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ZeroJunk

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Next time use acid. It won't remove the plating like sanding can.
Provided you don't have gouges above the exhaust port you will probably be ok.
Stihl 661 cylinder and piston kit can be had for $289 on Ebay.
I did use muratic acid. About, four doses with a Q-tip with the cylinder heated. Some 400 grit, and Wigglesworth Scotch Brite method.
I've likely done 100 of these. This much transfer requires a lot of work. And, if you leave just a little it will get in a ring groove just as sure as the world.
But, all advice is appreciated.
 

ZeroJunk

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That's another myth that never dies the one about high octane fuel burns slower and makes less power lol
High octane is fine to use in saws only downside is it usually costs more. The flame front burns just as fast as low octane and sometimes depending on the fuel high octane can have a faster burning flame front. The only thing high octane does different is having a better resistance to detention it does not contain less "powers" as the myth would have us believe.
Octane is nothing more than a knock rating with pure 2,2,4-Trimethylpentane setting the 100 standard. I forget what 1 is. But, it is a range of resistance to pre detonation or knocking. I think some of the highest ever used was in the WW II B-29 bombers, maybe others. Think it was around 140 and green. I used to buy 108 back in the day. It was purple.
You can run more compression and advanced timing . But, thinking it runs hotter or will burn up your whatever is incorrect.
I think I can still get 104 unleaded up the road, for a price.
 

Brushpile

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That's another myth that never dies the one about high octane fuel burns slower and makes less power lol
High octane is fine to use in saws only downside is it usually costs more. The flame front burns just as fast as low octane and sometimes depending on the fuel high octane can have a faster burning flame front. The only thing high octane does different is having a better resistance to detention it does not contain less "powers" as the myth would have us believe.
I've used 93 octane ethenol free and red armor 50/1 in all my echo equipment since 2015 and have no reason to do differently. Same equipment, ran quite hard at times, still cranks on first or second pull. That's a necessity with my neck issues. If it won't start quick I got no use for it. May eventually have to go all electric if that ever becomes a viable option. But for now... 👍
 

OM617YOTA

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Octane is nothing more than a knock rating with pure 2,2,4-Trimethylpentane setting the 100 standard. I forget what 1 is. But, it is a range of resistance to pre detonation or knocking. I think some of the highest ever used was in the WW II B-29 bombers, maybe others. Think it was around 140 and green. I used to buy 108 back in the day. It was purple.
You can run more compression and advanced timing . But, thinking it runs hotter or will burn up your whatever is incorrect.
I think I can still get 104 unleaded up the road, for a price.

Heptane is zero octane.
 

Hermio

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Hermio, yes I do have doubts you are an engineer. If only because what you have said and and the logic you are using.
If what I said is not logical, prove it. And what are your qualifications, pray tell? You have knocked several people who have actually studied oils, and have knocked Project Farm, which, although one can question some of his methodology, it is far from rubbish. If anything, Todd of Project farm is extremely thorough and conscientious in all of his testing. In any case, I could certainly prove I am an engineer. You would probably not accept such proof, however. Your viewpoint is that anyone who disagrees with you cannot be an engineer, and you call their opinions rubbish or worse. Ironically, I did not entirely disagree with you. What I said is that there is an optimum oil mix ratio for a given combination of oil, engine and gasoline; that more oil is not better beyond a certain point. That is indisputable. I also said that I do not know what that ratio is, so I am inclined to trust manufacturer recommendations. For others who are interested in standard testing, I offer the following resources.
ISO Two-Cycle Oil Specifications - oilspecifications.org



Standard Test Method for Determination of Lubricity of Two-Stroke-Cycle Gasoline Engine Lubricants (Withdrawn 2022) (astm.org)



Performance Test Methods for Two-Stroke Cycle Engine Lubricants Including Lean Fuel-Oil Ratio Conditions (sae.org)



Certification - TC-W3 (nmma.org)



Hey All (wdarc.org)



2T_2018_EV1912.pdf (jalos.or.jp)



Development of JASO 2-Stroke Engine Oil Standards (sae.org)



https://oilordering.com/product-detail/saber-professional-synthetic-2-stroke-oil/ (scroll down to the tests on this one)
 
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That's another myth that never dies the one about high octane fuel burns slower and makes less power lol
High octane is fine to use in saws only downside is it usually costs more. The flame front burns just as fast as low octane and sometimes depending on the fuel high octane can have a faster burning flame front. The only thing high octane does different is having a better resistance to detention it does not contain less "powers" as the myth would have us believe.
I've been preaching this exact thing on this site for years.. guys just can't let the old wives tales go. The other big one is high octane is more difficult to ignite. It's not.
Detonation takes exposure to heat and time. The faster you can get the combustion event over the less chance of detonation you have.
 
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I did use muratic acid. About, four doses with a Q-tip with the cylinder heated. Some 400 grit, and Wigglesworth Scotch Brite method.
I've likely done 100 of these. This much transfer requires a lot of work. And, if you leave just a little it will get in a ring groove just as sure as the world.
But, all advice is appreciated.
If they are that bad I'd be looking at the ebay cylinder kit I mentioned..
 
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If what I said is not logical, prove it. And what are your qualifications, pray tell? You have knocked several people who have actually studied oils, and have knocked Project Farm, which, although one can question some of his methodology, it is far from rubbish. If anything, Todd of Project farm is extremely thorough and conscientious in all of his testing. In any case, I could certainly prove I am an engineer. You would probably not accept such proof, however. Your viewpoint is that anyone who disagrees with you cannot be an engineer, and you call their opinions rubbish or worse. Ironically, I did not entirely disagree with you. What I said is that there is an optimum oil mix ratio for a given combination of oil, engine and gasoline; that more oil is not better beyond a certain point. That is indisputable. I also said that I do not know what that ratio is, so I am inclined to trust manufacturer recommendations. For others who are interested in standard testing, I offer the following resources.
ISO Two-Cycle Oil Specifications - oilspecifications.org



Standard Test Method for Determination of Lubricity of Two-Stroke-Cycle Gasoline Engine Lubricants (Withdrawn 2022) (astm.org)



Performance Test Methods for Two-Stroke Cycle Engine Lubricants Including Lean Fuel-Oil Ratio Conditions (sae.org)



Certification - TC-W3 (nmma.org)



Hey All (wdarc.org)



2T_2018_EV1912.pdf (jalos.or.jp)



Development of JASO 2-Stroke Engine Oil Standards (sae.org)



https://oilordering.com/product-detail/saber-professional-synthetic-2-stroke-oil/ (scroll down to the tests on this one)
It's not logical to hype a home brewed test with poor methodology. In fact this would drive most engineers I know crazy.
 

skeet88

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It's not logical to hype a home brewed test with poor methodology. In fact this would drive most engineers I know crazy.
Not trying to be a smart axx , but what would you recommend for a proper test to compare mix ratios? You may have already mentioned it , if so I will go back and try to find it. Be Safe!
 

MikeRock

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The best fuel you can run in your saws is ethanol-free. The octane rating doesn't mean squat until you reach a compression high enough that detonation becomes an issue.
Thank you, that is what I hoped. Now I wish we could add the lead back in, but the greenies would have a heart attack..... so let's go for it!!
Thanks again,
God bless,
Mike
 

MikeRock

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That's another myth that never dies the one about high octane fuel burns slower and makes less power lol
High octane is fine to use in saws only downside is it usually costs more. The flame front burns just as fast as low octane and sometimes depending on the fuel high octane can have a faster burning flame front. The only thing high octane does different is having a better resistance to detention it does not contain less "powers" as the myth would have us believe.
Again, my thanks.
 
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Not trying to be a smart axx , but what would you recommend for a proper test to compare mix ratios? You may have already mentioned it , if so I will go back and try to find it. Be Safe!
I would start by adding data loggers to saws used in a professional manner. Say 50 with loggers and 50 with arborists. I would then compare operating conditions, IE throttle opening, CHT, EGT etc. I would use this data to set up a test regime using variable load water break dynos. I then would set up a test using climate controlled dynos with 15 or more engines. They would be fueled with reference fuel of the same lot number. The load on the test engines would be variable to mimic real life use. I would also run the tests to 300 hours. Tear down and document, then run then test another 300 hours and repeat until failure.
Even doing this you wouldn't get real life results, but you should see a trend.
Next I would send 15 more controlled carb saws with each ratio to the field with reference fuel and run an extended field test with the same hours run and tear down schedule to confirm what was observed under controlled conditions.
No one is going to do this though. To much cost for not enough benefit.
Instead you get half baked tests like Amsoil did that's posted above.
 
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I doubt you could get one back in shape, but I can .
I've used the acid trick before to save one off ported cylinders or those that are no longer available.
I wouldn't waste my time doing such when I new OEM piston and cylinder kit can be had for less than $300 bucks.
It's not a flex to half ass chit together. And it's certainly not a flex to fix a two stroke chainsaw as they are dead simple..
 

Smitty Smithsonite

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I've seen back to back dyno tests on a Ninja 900 that lost 3-4 RWHP going from 94 octane Sunoco to Cam 2 106 octane leaded race fuel. I suppose it could have been the lead displacing fuel, since we didn't have ethanol or MBTE in those days, but from that point on I was lead to believe that you'll lose a little power using a higher octane than the engine needs.
 
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I've seen back to back dyno tests on a Ninja 900 that lost 3-4 RWHP going from 94 octane Sunoco to Cam 2 106 octane leaded race fuel. I suppose it could have been the lead displacing fuel, since we didn't have ethanol or MBTE in those days, but from that point on I was lead to believe that you'll lose a little power using a higher octane than the engine needs.
Most likely do to the distillation curve of the fuel and not the octane.
Many two strokes lose power on race fuels that have distillation curves not optimized for a two cycle motor.
It's this reason that companies like VP sell many different fuels for different applications.
 

MacAttack

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There seems to be a theme on this thread among some folks that "50:1 or 40:1 are OK for the occasional homeowner use, but less than 32:1 is going to wipe out the bearings with professional, daily use" or to that effect.
When I worked at a tree service, all we EVER used were the 50:1 bottles of Husky XP oil in a gallon gas can in EVERYTHING. And Im talking Husky 332 climbing saws, 357xp and 372xp ground saws, some older 272's, and a 3120. Those saws got the PISS ran out of them day after day, month after month, for years, and there was never a bottom-end failure. Hours upon hours bucking up big old cottonwoods, elm, spruce and whatever we were dropping.
That's my firsthand experience, doesn't mean 32:1 couldn't make them last even longer though, but more use than the average guy would ever put on his bottom end bearings.
 

Sawdust Man

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There seems to be a theme on this thread among some folks that "50:1 or 40:1 are OK for the occasional homeowner use, but less than 32:1 is going to wipe out the bearings with professional, daily use" or to that effect.
When I worked at a tree service, all we EVER used were the 50:1 bottles of Husky XP oil in a gallon gas can in EVERYTHING. And Im talking Husky 332 climbing saws, 357xp and 372xp ground saws, some older 272's, and a 3120. Those saws got the PISS ran out of them day after day, month after month, for years, and there was never a bottom-end failure. Hours upon hours bucking up big old cottonwoods, elm, spruce and whatever we were dropping.
That's my firsthand experience, doesn't mean 32:1 couldn't make them last even longer though, but more use than the average guy would ever put on his bottom end bearings.
This pretty much sums up my personal experience as well...
Husky or even Stihl oil, mixed at 50:1. Run the saws for hours a day full time for years never had a problem with premature death of saws.....
 

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