# Octane ?  What do you put in your saw?



## basswidow (Mar 5, 2010)

I have been using 87 octane.  I had a chainsaw dealer (Dolmar) tell me to run high octane 93.   Is that just for more power?  

What do you run in your saw?


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## smokinj (Mar 5, 2010)

I think they run better on 93 seem to start a little easier and a little better throttle response. On the very large cuts I also think it keep the rpm up may all be in my head but makes me fill better. (all warm and fuzzy)


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## karri0n (Mar 5, 2010)

Ideally you would want gasoline that contains no ethanol. As far as Octane, I'm really not sure what the advantages would be(that's not to say there are none, I'm sure someone will chime in)

My understanding of Octane is that higher octane fuel will not ignite as quickly as lower octane fuel. It does not contain any more BTU's than lower octane, but the ability of the cylinder to operate at a higher temp(and therefore higher compression) without the fuel autoigniting translates into more power. This makes sense to me in a fuel injected, computer controlled environment, as the computer will know that the fuel is burning stoichometrically and can adjust the fuel and air ratios to achieve maximum power. If gasoline autoignition occurs, the knock sensor will tell the ECU, which will tell the injectors to step down the ignition timing. Higher octane means autoignition will occur at a higher temperature and compression, so the cylinder can operate at higher efficiency and power than lower octane fuel.

All the info I have on this is based on automotive applications; in a small-engine, carburated,  2 stroke application, this could all go right out the window. Maybe the carburetors are pre-tuned to burn 93 octane fuel without premature ignition.


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## webie (Mar 5, 2010)

smokinjay said:
			
		

> I think they run better on 93 seem to start a little easier and a little better throttle response. On the very large cuts I also think it keep the rpm up may all be in my head but makes me fill better. (all warm and fuzzy)


+ 1 especially the warm and fuzzy part


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## basswidow (Mar 5, 2010)

yeah - ethanol is bad.  

What about if you run 93 - could cause your saw to run hotter or lean?  Or is the running lean merely a function of not having the oil mix right?

Do you run 93 in all your 2 stroke equipment?  I've just been using 87.  Not sure if I need to change that or not?


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## smokinj (Mar 5, 2010)

basswidow said:
			
		

> yeah - ethanol is bad.
> 
> What about if you run 93 - could cause your saw to run hotter or lean?  Or is the running lean merely a function of not having the oil mix right?
> 
> Do you run 93 in all your 2 stroke equipment?  I've just been using 87.  Not sure if I need to change that or not?



running lean would be carb out of adjustment...and yes I run 93 in all my 2 cycles.......93 will not make it run lean or hot!
If the limit caps are in place you will not ever run to lean.


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## basswidow (Mar 5, 2010)

OK - so it will just make the saw run better..... purr.  I will try some next time.


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## ikessky (Mar 5, 2010)

My FIL was having trouble with a few of his saws.  When he was at the service center, the guy told him to switch to 91-93.  He hasn't any issues since!  Based off that, I haven't run less than 91 in any of my small engines.


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## Deere10 (Mar 5, 2010)

I only run 93 in my saw. Never any problems. Thats what the dealer said to run in the Husky and it loves it  never one carb problem.I also mix synthetic 2 stroke oil with it...... OOO no did i open up a whole can of worms there??


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## smokinj (Mar 5, 2010)

Deere10 said:
			
		

> I only run 93 in my saw. Never any problems. Thats what the dealer said to run in the Husky and it loves it  never one carb problem.I also mix synthetic 2 stroke oil with it...... OOO no did i open up a whole can of worms there??



lol maybe.....grab your popcorn...


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## aussiedog3 (Mar 6, 2010)

Stoichometrically??????    Whaaaaaaat???


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## SWNH (Mar 6, 2010)

FWIW, I run 93 in anything that has a carb.  From my experience, it seems to run better and doesn't go stale as fast as 87.


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## Nonprophet (Mar 6, 2010)

Ditto on the high octane and definitely avoid Ethanol  I'm lucky, one of only two gas stations in the whole country that sell non-ethanol gas is about 8 miles from my house.  People will drive from 30 miles away just to get the non-ethanol gas for their 2-stroke and outboard motors (even 4 stroke outboards!!).  Ethanol is the small engine and outboard mechanic's friend--a recent story in our local newspaper had an outboard motor repair shop stating that over 70% of their business comes from ethanol problems..........


NP


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## bogydave (Mar 6, 2010)

Octane: http://www.state.mn.us/mn/externalDocs/Commerce/Gasoline_Octane_Facts_102902052227_OctaneFacts.pdf

Octane additives in gas that is mixed with oil, no benefit, actually research shows the opposite. 

No more "bang for your buck" to buy high octane for 2 cycle engines. 

 It does burn slower & run cooler but the additional additives has a tendency to gum up pistons. Regular detergent gasoline is actually better. From some research I read for 2 cycles. 

Fill / top off the saw when you are going to use it, (fresh gas) don't fill it & let it set till next time you'll use it.
Keep your mixed gas in a sealed container & as cool as possible. Ever notice how the plastic jugs swell in the sun when out cutting? (my 2-1/2 gallon jug now holds 3 gal)
 As soon as you open the container, whoof, some high end are gone. If you smell it, it's flashing off. After 2 months or so of no use, dump the gas out of the saw & put in new .
Empty the tank if your not going to use you saw for a while. 

My buddy was a lab tech of  the Tesoro refinery here, told me unless it's a high performance sports car engine, waste of money. Fresh gasoline is more important.


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## richg (Mar 6, 2010)

Peter SWNH said:
			
		

> FWIW, I run 93 in anything that has a carb.  From my experience, it seems to run better and doesn't go stale as fast as 87.



A buddy of mine who runs a motorcycle/ATV repair shop told me that gas loses octane when it sits in storage, so it is prolly a good idea to start with a higher octane gas. He strongly recommended 93 octane + stabil+ octane boost for 2-stroke applications.


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## smokinj (Mar 6, 2010)

bogydave said:
			
		

> Octane: http://www.state.mn.us/mn/externalDocs/Commerce/Gasoline_Octane_Facts_102902052227_OctaneFacts.pdf
> 
> Octane additives in gas that is mixed with oil, no benefit, actually research shows the opposite.
> 
> ...




I guess they should contact stihl husky and dolmar I pretty darn sure they all call for at least 89-91 in the Manuel + it makes me fill better. (all warm and fuzzy)


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## stee6043 (Mar 6, 2010)

Lot's of fancy answers....all I can say is that I run 87 in my MS 310.  She starts fine, runs great and she cuts wood.  I like high octane beer, does that count for anything?


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## smokinj (Mar 6, 2010)

stee6043 said:
			
		

> Lot's of fancy answers....all I can say is that I run 87 in my MS 310.  She starts fine, runs great and she cuts wood.  I like high octane beer, does that count for anything?



yep as long as your getting the warm and fuzy part... but for real sthil has moved there min. octane rate to 91. I have more in my saws than trunk and the saws dont eat much so I run the 93... and there is some who run 100


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## Stubborn Dutchman (Mar 6, 2010)

smokinjay said:
			
		

> stee6043 said:
> 
> 
> 
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I wondered why the Stihl manual said to run mid-grade fuel. Don't remember where I read it but leaned that the oil lowers the octane to the point where detonation can occur and ruin the saw. It sounds plausible so I am running high test to be safe. Since I'm only cutting firewood for myself I don't go thru that much fuel anyway.


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## Tony H (Mar 7, 2010)

You need to run what the MFG states in the manual I think Stihl says 89. Since octane is only a figure used to express the resistance to detonation running anything higher than what's needed is a total waste of money. The oil companies have long tried to promote the higher grades ..... guess why more profits.
Fresh gas makes a difference and the chemicals like Stabil and Sea-foam do help to preserve the gas.
Just so you don't think I making this up I got the info from my BIL who has been a chemical engineer for Shell oil or whatever they are called now for the last 20 years. With modern cars it's even a little different , if the MFG says premium required vs recommended . Because the computer will adjust the timing the car "recommended" will run fine with regular with a little reduction in performance on full acceleration on the other hand the "required" car will probably suffer detonation on regular gas.


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## SmokinPiney (Mar 7, 2010)

Right now im runnin some VP 96 octane that was leftover from my bro-inlaws bike. The VP and motul race mix makes em run like ***** apes! Plus the smell is just awsome haha.


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## oldspark (Mar 7, 2010)

One of my Stihl manuals says at least 87, not sure if I can get the good stuff around here close, I have cut wood for over 30 years and not followed all the rules(gas is stored longer than recomended) but have never had a gas problem (rather be luckly that good).


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## Nonprophet (Mar 7, 2010)

Tony H said:
			
		

> You need to run what the MFG states in the manual I think Stihl says 89. Since octane is only a figure used to express the resistance to detonation running anything higher than what's needed is a total waste of money. The oil companies have long tried to promote the higher grades ..... guess why more profits.
> Fresh gas makes a difference and the chemicals like Stabil and Sea-foam do help to preserve the gas.
> Just so you don't think I making this up I got the info from my BIL who has been a chemical engineer for Shell oil or whatever they are called now for the last 20 years. With modern cars it's even a little different , if the MFG says premium required vs recommended . Because the computer will adjust the timing the car "recommended" will run fine with regular with a little reduction in performance on full acceleration on the other hand the "required" car will probably suffer detonation on regular gas.



Some motors are set up to run high octane, i.e. my Corolla XRS has a high-performance Celica GT-S engine that require 93 octane or higher fuel as stated in the manual.  My other Toyota (Tacoma) gets regular and runs just fine on that.

That being said, given the high-revving nature of 2-strokes and the fact that most people run their saw either idling or at wide-open throttle, I think it makes sense to provide the best fuel that I can.  Seeing as we're talking about a $.10 difference every time I mix up a gallon of chainsaw fuel, it really seems to be a no-brainer to use the higher octane fuel.


NP


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## DanCorcoran (Mar 7, 2010)

Okay, so I have a gallon of old (stale) fuel mix.  How do you dispose of it?


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## Kenster (Mar 7, 2010)

DanCorcoran said:
			
		

> Okay, so I have a gallon of old (stale) fuel mix.  How do you dispose of it?



I use old gas and oil to fuel my burn pile.


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## North of 60 (Mar 7, 2010)

stee6043 said:
			
		

> Lot's of fancy answers....all I can say is that I run 87 in my MS 310. She starts fine, runs great and she cuts wood. I like high octane beer, does that count for anything?



Now your talking. Canada is the home of high octain legal beer. The north even gets away with more on the shelf. :coolsmile:


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## Nonprophet (Mar 7, 2010)

DanCorcoran said:
			
		

> Okay, so I have a gallon of old (stale) fuel mix.  How do you dispose of it?



Thanks for doing the right thing and asking how to properly dispose of it--with nearly 7 billion of us on the planet now every little thing we can do to minimize our impact makes a difference!!

About 5 years ago we had 20 gallons or so of old diesel we needed to get rid of.  We didn't just want to dump it in the woods somewhere or burn it, so I called the local fire department, they had no suggestions.  I called the DEQ, they said that most places that do oil changes will take old fuel for free as they get paid for the old oil.  Another alternative they mentioned was to pour it into a shallow metal or plastic pan and place it in the sun where it would evaporate eventually.  I didn't want to worry about kids or pets coming into contact with it, so we took it to a local service station and they added it to their used oil container for free. 

NP


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## ChipTam (Mar 7, 2010)

Not sure about their saws but Stihl recommends high octane for their weed whips.  Since I read that in their manual and switched to high octane, the weed whip starts a lot easier.
ChipTam


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## Nonprophet (Mar 7, 2010)

Quoted from the Stihl MS361 manual:

"Use mid-grade unleaded gasoline with a 
minimum octane rating of  89 (R+M/2). If 
the octane rating of the mid-grade 
gasoline in your area is lower, use 
premium unleaded fuel.

Fuel with a lower octane rating may  
increase engine temperatures. This, in 
turn, increases the risk of piston seizure 
and damage to the engine.

The chemical composition of the fuel is 
also important. Some fuel additives not 
only detrimentally affect elastomers 
(carburetor diaphragms, oil seals, fuel 
lines, etc.), but magnesium castings and 
catalytic converters as well. This could 
cause running problems or even 
damage the engine. For this reason 
STIHL recommends that you use only 
nationally recognized high-quality 
unleaded gasoline!"

I checked 3 Husky manuals (455, 372, 395) and all three said minimum of 87 octane.


NP


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## smokinj (Mar 7, 2010)

Nonprophet said:
			
		

> Quoted from the Stihl MS361 manual:
> 
> "Use mid-grade unleaded gasoline with a
> minimum octane rating of  89 (R+M/2). If
> ...



and there you have it!!


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## wendell (Mar 8, 2010)

91, no ethanol here, Amsoil Sabre


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## StackedLumber (Mar 8, 2010)

can I get a vote for no-lead Aviation Gas?? (I believe oct. 100)  No ethanol-available at airports and some gas stations.  Saw runs great, and I don't have to worry about ethanol corrosion


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## ikessky (Mar 8, 2010)

Doesn't most of the pre-mix oil have a fuel stabilizer in it because of the ethanol now?

On many late model computer controlled cars, running a higher octane will allow the computer to advance the timing more.  It is still, however, controlled by the parameters of a stock chip/tune.


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## basswidow (Mar 8, 2010)

Really glad I posted this question.  I swear this IS the place to get answers and shorten the learning process.  When I posted - I thought the higher octane would burn hotter and be prone to cause more damage and my 87 octane was safer.  I was completely backwards with that line of thinking.  I am gonna burn 93 from here on out - not only in my chain saw, but also in my weedeater.  I should have also done the same in my outboard motor too.


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## Tony H (Mar 9, 2010)

DanCorcoran said:
			
		

> Okay, so I have a gallon of old (stale) fuel mix.  How do you dispose of it?



an easy was to git rid of a small amount like that is to add it to your truck when you do the next fill up ,mixed in with the rest of the fuel your engine will never know.


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## Tony H (Mar 9, 2010)

Nonprophet said:
			
		

> Tony H said:
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Your first sentence is correct and accurate. 
The second sentence buys into the old wifes tale if regular is good premium must be better .  
By your example if you rev your Tacoma hard and haul some weight then it should be using premium because some how that alters the engine compression and requires additional anti detonation protection ? Sound silly to you ?


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## Tony H (Mar 9, 2010)

basswidow said:
			
		

> Really glad I posted this question.  I swear this IS the place to get answers and shorten the learning process.  When I posted - I thought the higher octane would burn hotter and be prone to cause more damage and my 87 octane was safer.  I was completely backwards with that line of thinking.  I am gonna burn 93 from here on out - not only in my chain saw, but also in my weedeater.  I should have also done the same in my outboard motor too.



Don't forget the lawnmower, leaf blower, and the log splitter.  :red: 

I put premium in my splitter and ........ it split exactly the SAME as it did before. 

Sorry buy you got the wrong message higher octane will not help in any way with those engines.

Don't listen to me just google premium gas and see all the articles by : automotive publications, scientists and engineers from big oil companies, car companies , FTC and other gov sources that will confirm this is true.
The only one you might have trouble finding is one from an oil company.


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## FireAnt (Mar 9, 2010)

Tony +1. Octane has to do with engine compression. Everyone may know this but I put it up. 

Higher octane ratings correlate to higher activation energies. Activation energy is the amount of energy necessary to start a chemical reaction. Since higher octane fuels have higher activation energies, it is less likely that a given compression will cause autoignition.

It might seem odd that fuels with higher octane ratings are used in more powerful engines, since such fuels ignite less easily. However, an uncontrolled ignition is not desired in an internal combustion engine. The fuel must be fired at a precise time. An ignition too early will cause the resulting forces to try to turn the crankshaft in the reverse direction. This will not cause the engine to rotate in the reverse direction because of the kinetic energy in the rotating assemblies and the flywheel, but will strain the crankshaft. This strain is the source of the characteristic 'ping' noise heard during detonation. This reduces power output, because much of the energy is absorbed as strain and heat in parts of the engine,[citation needed] rather than being converted to torque at the crankshaft.

A fuel with a higher octane rating can be run at a higher compression ratio without causing detonation. Compression is directly related to power (see engine tuning), so engines that require higher octane usually deliver more motive power. Engine power is a function of the fuel, as well as the engine design, and is related to octane rating of the fuel. Power is limited by the maximum amount of fuel-air mixture that can be forced into the combustion chamber. When the throttle is partially open, only a small fraction of the total available power is produced because the manifold is operating at pressures far below atmospheric. In this case, the octane requirement is far lower than when the throttle is opened fully and the manifold pressure increases to atmospheric pressure, or higher in the case of supercharged or turbocharged engines.

Many high-performance engines are designed to operate with a high maximum compression, and thus demand high-octane premium gasoline. A common misconception is that power output or fuel mileage can be improved by burning higher octane fuel than a particular engine was designed for. The power output of an engine depends in part on the energy density of its fuel, but similar fuels with different octane ratings have similar density. Since switching to a higher octane fuel does not add any more hydrocarbon content or oxygen, the engine cannot produce more power.

However, burning fuel with a lower octane rating than required by the engine often reduces power output and efficiency one way or another. If the engine begins to detonate (knock), that reduces power and efficiency for the reasons stated above. Many modern car engines feature a knock sensor – a small piezoelectric microphone which detects knock, and then sends a signal to the engine control unit to retard the ignition timing. Retarding the ignition timing reduces the tendency to detonate, but also reduces power output and fuel efficiency.

Most fuel stations have two storage tanks (even those offering 3 or 4 octane levels), and you are given a mixture of the higher and lower octane fuel. Purchasing premium simply means more fuel from the higher octane tank. The detergents in the fuel are the same.

The octane rating was developed by chemist Russell Marker at the Ethyl Corporation c1926. The selection of n-heptane as the zero point of the scale was due to the availability of very high purity n-heptane, not mixed with other isomers of heptane or octane, distilled from the resin of the Jeffrey Pine. Other sources of heptane produced from crude oil contain a mixture of different isomers with greatly differing ratings, which would not give a precise zero point.


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## bogydave (Mar 9, 2010)

Tony H said:
			
		

> basswidow said:
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+2
Marketing is everything. 
If you ever get confused remember this : It is about the money $$


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## mainemaul (Mar 10, 2010)

i run hi test in all my small engines and they all love it,here in maine we have ethanol so i add STARTRON to everything that might sit and never have fuel issues


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## Tony H (Mar 10, 2010)

mainemaul said:
			
		

> i run hi test in all my small engines and they all love it,here in maine we have ethanol so i add STARTRON to everything that might sit and never have fuel issues



It's the additive that does it not the hi test , Stabil , Chevron techtron,wynns,and Starbright startron are all non alcohol additives .
Note most if the other additives add MORE ALCOHOL to your fuel and that's not what you want is it. Check the label on your favorite additive.


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## Bill (Mar 10, 2010)

Here is a web page to locate good gas, state by state

http://pure-gas.org/index.jsp?stateprov=WI


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## firefighterjake (Mar 10, 2010)

I used to run hi-test in the small engines (ie. chainsaw, tractor, weedbeater, etc.) but a long time ago I discovered that they pretty much run just as well with the cheap(er) stuff. Like Maine Maul I do use Star-Tron as a non-alcohol stabilizer in the fuel tanks when the equipment will be sitting for a while . . . which reminds me . . . I need to add some to my sled since I think sledding is done for the year here.


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## Tony H (Mar 10, 2010)

Smokey said:
			
		

> Here is a web page to locate good gas, state by state
> 
> http://pure-gas.org/index.jsp?stateprov=WI



Good info , here is another one just for Wisconsin

http://www.molonyrealestate.com/Ethanol_Free_Gas_Stations_in_Wisconsin.html

Wish I had some closer ones than Janesville thats about 25 minutes away.


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## Tony H (Mar 10, 2010)

firefighterjake said:
			
		

> I used to run hi-test in the small engines (ie. chainsaw, tractor, weedbeater, etc.) but a long time ago I discovered that they pretty much run just as well with the cheap(er) stuff. Like Maine Maul I do use Star-Tron as a non-alcohol stabilizer in the fuel tanks when the equipment will be sitting for a while . . . which reminds me . . . I need to add some to my sled since I think sledding is done for the year here.



I kept forgetting so now I add Stabil to the gas cans when I take them to get filled and all the small engines get treated gas.

Heck I have tried for a while now to convince my in laws they don't need to run everything "out of gas" because that leaves some remnants in the system anyway but to no avail. You should see them all running the boats out of gas when we are loading up after a trip. Hey that's what Grandpa taught them and that's good enough for them ...... then again Grandpa regularly hooks himself and his fishing partners and runs into the dock with the boat and they don't do that !!   :bug:


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## firefighterjake (Mar 10, 2010)

Tony H said:
			
		

> firefighterjake said:
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Have you checked to make sure it's the Sta-bil without any alcohol? I've heard the marine grade Stabil is good stuff.


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## Bill (Mar 10, 2010)

I started putting a little stabil or seafoam in all my gas cans when I fill them up. That way if something isn't run for a while or I have left over gas at the end of the year I know it's already treated. Those pint bottles last pretty long and it's cheap insurance. Maybe I just have too many toys.


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## lowroadacres (Mar 11, 2010)

I am starting to get frustrated reading this thread.

I am not aware of anywhere that I can buy gasoline without ethanol as it is mandated by law here in Manitoba that every gas station/fule company has to have a certain percentage of ethanol.

Any suggestions from around the wood burning world as to where I can get ethanol free fuel?

I am wondering about av gas or motorcycle racing fuel?


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## fyrwoodguy (Mar 11, 2010)

currently i run AV 100 LL fuel from the local airport,plus that's what goes into the new saws i sell too.i have run VP 105 unleaded race gas for years untill the fuel spiked to $9.00 per gal.which put me back to AV gas (which is where i started 20 years ago)


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## charly (Mar 11, 2010)

I've always ran 93 octane, amsoil, and seafoam. Never had any carb, fuel line, or diaphram issues, nothing. I can buy ethanol free gas by me, two different places. I was told the higher octane has less ethanol. Don't know how true that is. Something new I found, VP racing fuel came out with a new Small Engine Fuel: SEF 94. 94 octane and the web site states that it will soon be available in gallon and quart containers too. Not aware of a price yet. I read where AV Gas builds alot of deposits in two stroke motors. Some paramotor companies recommend  auto gas over AV gas.


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## Kenster (Mar 11, 2010)

I just a got a new MS390.  Haven't fired it up yet  but I've started reading the manual.  It clearly says to use hi octane gasoline.


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## Tony H (Mar 12, 2010)

fyrwoodguy said:
			
		

> currently i run AV 100 LL fuel from the local airport,plus that's what goes into the new saws i sell too.i have run VP 105 unleaded race gas for years untill the fuel spiked to $9.00 per gal.which put me back to AV gas (which is where i started 20 years ago)



the big advantage with av gas is not the high octane but the strict controls ment to prevent contamination and no alcohol is allowed.
this also means the fuel does not "go bad" or start to break down quickly (60-90 days) like automotive gas.
Planes are often stored or parked for longer times and would have much worse outcomes from a tank of old gas.

Here is a good article that explains mogas and avgas octane and ethanol and other facts about gas from the folks at Shell

http://www.shell.com/home/content/aviation/aeroshell/technical_talk/the_blue/issue_6_2007.html

Here is a sentence that everyone should read from the shell paper.

Octane rating is a measure of how resistant a fuel is to detonation; the higher the octane rating, the more the fuel / air mixture can be compressed without detonation happening. To make this clear, octane rating is not a measure of the amount energy in the fuel but is a measure of its resistance to detonation. The advantage or higher octane fuels is that a higher compression ratio or supercharging ratio can be used, which then leads to a higher volumetric efficiency within the engine, which in turn means more power output for a given fuel burn.


I hear you guys with no non ethanol stations in the area . Closest one to me is 20 minutes away so I add stabil instead and it seems to help as I usually get 20 gallons of gas at a time for all the small engines and it will last me a couple of months and maybe longer in the winter. I also leave fuel in lawn mowers , boats , jet skis, snow blowers and anything else from season to season and since using stabil the last 20 plus years have never had a fuel related problem with any engine. I even had a Mazda RX7 that sat for 5 years with stabil treated fuel and it started and ran perfect !


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## tiber (Mar 12, 2010)

The 93 octane thing (or 91) is because the gas has much better formulation than the 80-series stuff. It doesn't give you more power, run cooler, whatever - it simply has less of a chance to break down and covers up timing problems in the engine due to load or wear.

I run 93 to 102 octane in the MR2, I put the same thing in my chainsaw because I know it's never going to have an issue getting that stuff to touch off. Also the higher the octane, the less ethanol is in the gas. Ethanol is typically 75 to 80 octane, so 93 octane hardly has any.

Also I put used motor oil in my chainsaw but that's a different topic.


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## Redskins82 (Mar 14, 2010)

Smokey said:
			
		

> Here is a web page to locate good gas, state by state
> 
> http://pure-gas.org/index.jsp?stateprov=WI



Thanks for the link. The last time I saw it posted there was no station within 20 miles of me. Now the list has changed and the second to the closest gas station to my house is listed. It's less than a mile away. Excellent!

btw, I use nothing but 87 octane.


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## Redskins82 (Mar 14, 2010)

Why delete my posts when you'll allow someone to peddle ignorance like this? People don't need to be given such erroneous information.




			
				tiber said:
			
		

> Also the higher the octane, the less ethanol is in the gas. Ethanol is typically 75 to 80 octane, so 93 octane hardly has any.



"Starting with the 2007 Indy race season, the race vehicles will run on E100, 100 percent ethanol. Pure Ethanol (E100) has an octane rating of 113, as compared to straight gasoline which has an octane rating of 87 to 92."

http://e85.whipnet.net/news/indy.ethanol.html

"Ethanol is a high-octane fuel. Octane helps prevent engine knocking and is extremely important in engines designed to operate at a higher compression ratio, so they generate more power."

http://www.afdc.energy.gov/afdc/ethanol/what_is.html

"Pure ethanol (E100) fuel has a higher octane rating of 106 RON compared to gasoline’s 95 RON. Using a 12:1 compression ratio and twin turbochargers running at 1.0 bar boost, the Aero X BioPower engine delivers a hefty 143hp per liter displacement. Turbocharging with E100 fuel allows the use of a higher compression ratio—giving more engine power—than is possible with gasoline because of the risk of harmful knocking (pre-detonation)."

http://www.greencarcongress.com/2006/02/gm_introduces_4.html

"The CCX Edition runs on regular petrol and produces 888 Bhp, whilst the CCXR Edition has been modified as a bioflexfuel car, and can run E85, E100, regular 98 octane petrol (Europe) or a mixture of the three. When run solely on petrol, the engine produces 888 Bhp, but the higher octane E85 fuel makes higher compression, boost pressure and increased spark advance possible, enabling the engine to deliver a staggering 1018 Bhp."

http://www.koenigseggedition.com/

Do I need to post more links?


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## tiber (Mar 14, 2010)

Redskins82 said:
			
		

> Why delete my posts when you'll allow someone to peddle ignorance like this? People don't need to be given such erroneous information.



Well, that's fine if you're buying your gas from NASCAR, but I believe the thread is about buying gas from the gas station. I don't think anyone is going to the _ethanol_ station and filling up their chainsaw. Let me explain myself.

There is no "standard formulation" of gasoline, or gasoline/ethanol blends. If you google for "what is gasoline" a recipe won't come up. A better discussion would be to compare who's gas (as in sunoco, exxon, whatever have you) seems to store best. We can only speak in the most general sense when it comes to arguing about who's gas has what in it.  

Now, where the higher octane = less ethanol metric comes from is the SCCA. After MTBE was made illegal, those of us who ran cars which needed it either had to turn the boost down or figure out who had the least ethanol. (Or apply for a permit, pffft) Problem being ethanol, when blended, is a great fuel, but our cars ran on gasoline. Would you put diesel in your engine? Kero? Fuel from the space shuttle? These might burn well, but the bottom line is they're different from gasoline the same way coal wouldn't burn well in a wood stove. The gas picks up water, eats the fuel lines, and frankly there's no difference between a "summer car" engine and your chainsaw except the chainsaw sees intermittent use all year round.

Common sense arguments aside, I didn't want to plug a specific brand in my post, but since we're down to it - Sunoco Marine Super blend is known to have little to no ethanol and Sunoco GT runs ads specifically saying it also does not contain methanol. 

*EDIT:* Found the sunoco blend - 260GTX is what you need to use in the bracket which forbids ethanol. If you're looking for the 260GT blend (federal minimum for road use), you can find a station. If you want to go for the gold and buy nonstreetable gasoline, find a dealer.

I really hope I don't come off sounding like a sunoco commercial, but they make good stuff.


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## flewism (Mar 14, 2010)

I didn't read this hold thread, but I run 93 or better octane in my saws and boats, 87 in everything else.  All small engines  get stabil come fall,  except the diesels.

This is what works for me.


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## Rich L (Mar 14, 2010)

If I recall correctly the Stihl manual says use 89 octane.That's what I use with no problems so far.


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## Nonprophet (Mar 14, 2010)

Redskins82 said:
			
		

> Why delete my posts when you'll allow someone to peddle ignorance like this? People don't need to be given such erroneous information.



Your post was probably deleted because it wasn't very nice--i.e. calling people "goobs" or whatever.  I see by your post count that you're relatively new here, one thing you'll (hopefully) quickly learn is that for the most part people are very friendly and helpful here.  Name-calling doesn't really fit in very well.

NP


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## smokinj (Mar 14, 2010)

To each is own I have a large investment in my saws and I will run 93 or better, it just makes me fill all warm and fuzzy!


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## oldspark (Mar 15, 2010)

Our regular unleaded is 87 octane and the gasahol is 89, just saying.


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