# 25:1?



## SolarAndWood (Oct 26, 2009)

I inherited a Shindaiwa 416.  It is labeled 25:1?  I drained the tank, cleaned the plug and filled with fresh fuel.  Fired right up after not running for a long time.  Anything inherently different about the saw other than the mix?  I couldn't find anything other than than the parts manual.  Was this ever a common mix?


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## sedanman (Oct 26, 2009)

It was once a common mix ratio. The difference between then and now is not the engines but the oils. Oils have gotten much better in modern times and a good modern 50:1 oil would work just fine. I know there will be skeptics and you might not feel comfortable running the saw with so little oil so just go ahead and mix modern oil at 25:1 you won't hurt anything doing it that way either, just make more smoke. I have run my Dolmar 7900 on OPTI at 75:1 with no problems.


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## HittinSteel (Oct 26, 2009)

Listen to sedanman. I have an old 041 one that calls for 25:1. I run 50:1 stihl ultra and the piston and cylinder are perfect. If you run at 25:1 you will get carbon buildup. Won't kill the saw but will make more cleanup maintenance for yourself as the carbon builds and is just not necessary.


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## smokinj (Oct 26, 2009)

Same here!


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## Nonprophet (Oct 26, 2009)

I run 40:1 in my Stihl MS-440 and Husky 55 rancher even though they call for 50:1.  I also use high-test, non-oxygenated/EPA gas.  It may smoke a little more at 40:1, but I've heard of too many people "leaning-out" their 2 stroke stuff with the newer fuels, and I don't feel like burning up my saws and/or string trimmer.

NP


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## SolarAndWood (Oct 26, 2009)

Cool thanks.  50:1 with 93 octane worked fine for the 1/2 hour or so I ran it yesterday although I didn't run it hard.  Something tells me it would never get used if it needed its own mix.  Which would be a shame because it seems like a nice little saw.


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## sedanman (Oct 26, 2009)

Lean siezure of a 2 cycle engine is due to a lean air fuel mixture which runs extremely hot. The high operating tempuratures are the root cause of failure not lack of lubrication. If you took two identical new saws and ran one full tank of mix through each one then blocked off the air supply to the flywheel of one (making it run hot) and ran it on good mix it would die sooner that the other saw with good airflow running on straight gas with no oil. The overheated saw would die before it consumed a tank of fuel, the straight gas saw would run few 3 or 4 tanks before it craoked. Stihl performs this demonstration for their gold level students, I have seen it with my own eyes. The EPA has killed more saws with their tight emissions standards (lean air fuel mixture) than all of the straight gas horror stories you have ever heard.


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## madrone (Oct 27, 2009)

The ICS concrete cutting chainsaw I use at work calls for 25:1.


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## HittinSteel (Oct 27, 2009)

sedanman said:
			
		

> Lean siezure of a 2 cycle engine is due to a lean air fuel mixture which runs extremely hot. The high operating tempuratures are the root cause of failure not lack of lubrication. If you took two identical new saws and ran one full tank of mix through each one then blocked off the air supply to the flywheel of one (making it run hot) and ran it on good mix it would die sooner that the other saw with good airflow running on straight gas with no oil. The overheated saw would die before it consumed a tank of fuel, the straight gas saw would run few 3 or 4 tanks before it craoked. Stihl performs this demonstration for their gold level students, I have seen it with my own eyes. The EPA has killed more saws with their tight emissions standards (lean air fuel mixture) than all of the straight gas horror stories you have ever heard.




Good post. That's why I like to help my saws breath with an exacto knife for the limiter tabs and a dremel!!


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## ROBERT F (Oct 28, 2009)

Find one mix ratio, tune to that ratio and off you go.If your going to run 25-1 keep spare plugs handy.


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## SolarAndWood (Oct 28, 2009)

I don't have/can't find a manual for this saw.  It ran well for the half hour that I ran it as-is with 50:1 in it.  How would I know if I have to adjust the mixture?  And, if i do, is it the knob with the spring under it?


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## billb3 (Oct 28, 2009)

I had an engine  that wanted  100:1.
Can't remember if it was a saw, weedwhacker or the old British seagull .
Always did 50:1.

My stihl manual claims need for  high test  but I've had two service guys  claim regular or the saw will run (too) hot.
Original plug  on a  (aroundabout) 10 year old saw. Might be older. 026 pro.


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## dogsluvtrux (Oct 28, 2009)

Alot of the older two stroke stuff ran 25:1, but oil quality has improved immensely in just the last few years, use a good quality oil and 50:1 should be fine.  I also have some customers that run an opti-mix that is labeled for any two stroke mix.


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## Gooserider (Oct 28, 2009)

SolarAndWood said:
			
		

> I don't have/can't find a manual for this saw.  It ran well for the half hour that I ran it as-is with 50:1 in it.  How would I know if I have to adjust the mixture?  And, if i do, is it the knob with the spring under it?



You might try Arboristsite to see if anyone there can point you at a downloadable manual (I assume you've checked the Shindy site already)...  Essentially you can tell if the saw needs tuning by the way it runs, and if you want to get fancy, by using a tachometer on it.  Madsens has some downloadable audio files of what a good saw should sound like, and some good generic tuning instructions.

Don't know what that knob with spring might be, but it doesn't sound like a carb adjustment - possibly a manual oiler or the choke?

The usual setup for carb adjustments is three small screws that will be pretty close to each other, one does the high speed mix, one does the low speed mix, and one sets the throttle mix at low speed. They will be on the carb, and most of the time I see them on the left side of the saw at the junction between the engine and the air cleaner cover.  You want to end up with a saw that runs smoothly at full throttle, idles smoothly at a speed that does NOT move the chain when the brake is off, and transitions smoothly in between.  If you can't find a manual, follow the Madsen's instructions.

Gooserider


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## SolarAndWood (Oct 28, 2009)

Gooserider said:
			
		

> The usual setup for carb adjustments is three small screws that will be pretty close to each other, one does the high speed mix, one does the low speed mix, and one sets the throttle mix at low speed. They will be on the carb, and most of the time I see them on the left side of the saw at the junction between the engine and the air cleaner cover.  You want to end up with a saw that runs smoothly at full throttle, idles smoothly at a speed that does NOT move the chain when the brake is off, and transitions smoothly in between.  If you can't find a manual, follow the Madsen's instructions.
> 
> Gooserider



Thanks, right next to the knob with the spring are two little adjustments labeled H and L.  The knob is definitely not the choke.  Maybe it was already adjusted for 50:1 because it behaves exactly as I would expect.  Sounds like I should put some time on it and see what it does.


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## sedanman (Oct 29, 2009)

Ok it gets hairy from here on out. If you have your saw adjusted for a perfect air fuel mixture with a fuel oil ratio of 25:1 and then switch to a fuel oil ration of 50:1 you have made the air fuel ratio a tiny little bit RICHER. The carb meters the contents of the tank and mixes them with air, for every drop of oil it allowed in it used to allow 25 drops of fuel, not for every drop of oil you get 50 drops of fuel. It is a miniscule change in air fuel ratio but it IS in the right direction. I am taking license with how the carb works to make my point.


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## Gooserider (Oct 29, 2009)

SolarAndWood said:
			
		

> Gooserider said:
> 
> 
> 
> ...



In that case, I might guess that H is the high speed mix, and L is the low speed mix, while your knob changes the throttle stop...  However this is just guessing on my part, hopefully someone that actually knows the saw can give a more definite answer.  

You might also be able to tell if you take the cover off and look at the carb...  The mix screws will definitely go into the carb body, the throttle stop can either be internal, or external where it will change the point to which the carb can close when you let go of the trigger...

Gooserider


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## ROBERT F (Oct 29, 2009)

The one with the spring is usually the Idle adjustment, to set idle air adjustment, ether by holding the butterfly open or stopping the slide on a slide carb.  Has to do with air flow across the transition port and idle air flow.  Can affect idle speed and off idle performance.  Idle speed itself is actually a balance between low speed mixture and position of air controlling device.  The biggest thing with changing oil mixtures is on the high speed side, as different mix ratios will give different  "power bands" and could cause slight bogging or overrevving.  This is true with one brand of oil to the next, and even synthetic to blended to organic.  Of course these changes are miniscule, but thats why two of my saws run on one ratio and one runs on another.  Even my two stroke bikes run two different types of oil, at the same ratio.  But then I'm a performance freak.


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## SolarAndWood (Oct 29, 2009)

Thanks.  It is running fairly well, I am going to run a few tanks of high test/50:1 mix through it and see where I am at.  I don't run the saws and trimmers enough to justify keeping more than one tank of mix around.


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## SnowTraveler (Oct 29, 2009)

There is an American synthetic oil company that makes a fantastic 2 stroke pre-mix oil recommended for up to 100:1 in ANYTHING.
I have run all of my 2 stroke equipment at 80:1 for over 20 years, saws, weed wackers, snowmobiles, dirt bikes, leaf blower, etc, etc. without a single problem.  I have a high CI and maintain my equipment very well.   I have recommended this oil to many, many friends and everyone has had great luck.  I know it is good, because I have a huge "weedwacker" industrial brush cutter from the '70's that I use the heck out of, and they stress 25:1 on the label, I have been running it at 80:1 for 20 + years.   I am also a firefighter, and our demolition saws on the fire apparatus run at 100:1 on this same oil.  Not sure what the rules are here, so I won't post the brand yet unless someone asks.


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## Gooserider (Oct 29, 2009)

Snow Traveler said:
			
		

> There is an American synthetic oil company that makes a fantastic 2 stroke pre-mix oil recommended for up to 100:1 in ANYTHING.
> I have run all of my 2 stroke equipment at 80:1 for over 20 years, saws, weed wackers, snowmobiles, dirt bikes, leaf blower, etc, etc. without a single problem.  I have a high CI and maintain my equipment very well.   I have recommended this oil to many, many friends and everyone has had great luck.  I know it is good, because I have a huge "weedwacker" industrial brush cutter from the '70's that I use the heck out of, and they stress 25:1 on the label, I have been running it at 80:1 for 20 + years.   I am also a firefighter, and our demolition saws on the fire apparatus run at 100:1 on this same oil.  Not sure what the rules are here, so I won't post the brand yet unless someone asks.



Rules on pricing, brand names, and so forth are a bit fuzzy, essentially it boils down to the idea that the Hearth is not a shopping or advertising venue (other than the banner adds that Craig gets paid for) and we don't want people treating it as one, but mentioning a brand name in context where it's helpful is OK...  It only gets to be a problem if we start to feel like a poster is only here to "pimp" for his favorite product, or an "industry member" starts pushing his business or product more than he is being helpful...  It's a bit of a judgement call, but product reviews almost always are OK to mention names - it's actually sort of frustrating when people don't as in "there's this geat product, but I won't tell you what it's called..."

Most of us are aware of Amsoil, which is what I'm guessing you are using, but your review is nice in terms of saying that you've had good luck with it...

Gooserider


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## SnowTraveler (Oct 29, 2009)

"Most of us are aware of Amsoil, which is what I’m guessing you are using, but your review is nice in terms of saying that you’ve had good luck with it…"

I had hoped that you would recognize the brand, I don't like pushing my faves on forums because it usually invites a flame war, but did want to share how good this product is.  Thanks!!


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## Gooserider (Oct 29, 2009)

Snow Traveler said:
			
		

> "Most of us are aware of Amsoil, which is what I’m guessing you are using, but your review is nice in terms of saying that you’ve had good luck with it…"
> 
> I had hoped that you would recognize the brand, I don't like pushing my faves on forums because it usually invites a flame war, but did want to share how good this product is.  Thanks!!



Not a problem, like I say it's kind of a fuzzy line, but there is a difference between "I use brand X with good / bad / indifferent results" and "YOU should use brand X"  - stuff that is done in the nature of a product review that is appropriate to the context of the thread is fine, I will post such myself...  It is especially not a problem if a person posts on different topics a reasonable amount... OTOH if someone only seems to post about their favorite product, and drags it into the discussion at the least excuse then we get to thinking "spammer" and it becomes an issue....  It's sort of like the famous Judges definition of porn - I know it when I drool over it...  ;-P 

Gooserider


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## EL DRIFTO (Oct 30, 2009)

flaming on a stove forum
hahahahahahahhahha

i modify cars for a hobby
i've converted some to e85 = 105 octane alcohol gasoline substitute for $1.85, uses 30% more
my relationship with gas goes back b4 the stove....

the only time i blended 2 cycle with e85, it coagulated to the bottom of the gas can.

it also acted like the weed eater had a performance pipe, although i never got it carbed to idle AND run.

there may be some resonance tuning issues with e burning slower & 2 cycles being heavily dependant on chamber tuning,

but, has anyone mixed or used e85 in their 2 cycle stuff ??

i wonder if amsoil would mix better with e85 ??


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## Gooserider (Oct 30, 2009)

Haven't tried doing E-85, fortunately they haven't tried sticking us with that in this area (YET!) but we pretty much can't avoid E-10.  From what I've heard, the present word from the OPE makers is that E-10 is OK as long as you are careful to keep moisture out of it, but that E-85 is emphatically not reccomended...

Gooserider


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## EL DRIFTO (Oct 30, 2009)

a couple of years ago when it first showed up here 
gas was $4, & i decided i could screw the gas man out of thousands a year if i could get my ford van to run on anyting else.
it's been in california for years.
but just got over to the east coast...
those guys with 1000 hp rabbits are having better luck than with C16 race fuel.
it's been greatly debated & widely understood that it's not actually green to anyting,
considering all the processing to make it.

but it is awesome race fuel !!
it's an alternative fuel, not a replacement for gasoline.
it usually takes up the mid octane spot on the pumps.

it seems that since 1986, govt law has been that all US gasoline has e10 btw.
just some fyi from my experiences.

all fuel system components in any thing after 1986 are e85 friendly.
although without 30% increase in fuel, it wont run.

as far as how bad it eats rubber & the whole thing
not since 86, although i've seen it chew right through a lawnmower fuel line, i dont think was that old.
replace hose & go on.


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## mjhfoster (Nov 17, 2009)

I just bought my first chainsaw yesterday, an ECHO GS35A with 350mm bar, 33cc and 3.8kg weight (sorry, we work in metric out here).

It should be good for what I need, cutting up small/medium sized logs from time to time.  I don't need anything large or expensive.  This cost me 31,000yen ($280ish), which is pretty good for Japan.

The maker (Echo) specify that it should have *25:1* gas/oil mix and this ratio is the standard here.  One can buy 25:1 ready mixed gas (petrol where I come from) in smallish quantities that make filling up easy and unnecessary to have a metal gas tank/mixing can and seperate gas and oil.  This is good for me with my small shed and garden.







I suppose the gas and oils are slightly different from country to country.  Anyway, I just wanted to post this.

I'll be using the chainsaw, with suitable protection of course, at the weekend on some cut-down cherry trees (free - yippee!).

Cheers, Matthew.


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## Gooserider (Nov 17, 2009)

Interesting...  Looks like the same basic saws that Echo sells here (W/ a 50:1 mix recommendation) except for the Japanese labeling on the side of the top cover...

Two things I can think of that might account for it - 

1. My understanding is that Japan doesn't have quite as tight emission standards, especially on small engines, as the US.  (I seem to recall hearing that Tokyo's air can get quite thick at times...)

2. As I recall reading about your vehicle mix in various bike magazines, you have a lot of small two-stroke motorcycles running around - probably many of them "legacy" vehicles that were built back in the days when 25:1 was the best ratio that makers could get by with - and it would be difficult to change all the existing infrastructure to support 50:1 without taking those older vehicles into account...  (The two stroke street bikes were never all that popular here in the US, and current emissions laws make them all but illegal, except for a few antiques)

Gooserider


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## mjhfoster (Nov 17, 2009)

Good information Gooserider.

I'll try the 25:1 but keep in mind the emissions.

All the newspaper distribution companies use 'moped' bikes that might very well have 2-stroke engines.  I can hear them if I'm up at 4 or 5am (not that often!) delivering the newspapers.


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## EatenByLimestone (Nov 17, 2009)

I was going through my father's basement and found a 6 pack of Homelite 16:1 2 cycle fuel.  There is an old Homelite chainsaw in the shed.  

Matt


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## Bubbavh (Nov 17, 2009)

40:1 or 50:1 will be fine look for a quality oil for "Air Cooled Engines".  Regular gas is better off because it doesn't sit in the tanks as long at the gas station.


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