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Discussion Starter #1
Reading over my manual on my new weedeater I am reading where it says used 89 octane at minimum and if the midgrade level of my area is lower than 89 to use premium. SAY WHAT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Just wanted to get you guys take on this. I havent used it yet
 

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Discussion Starter #3
Stihl considers these "high performance" engines, that's why premium or mid-grade fuel is recommended.
darn.

I guess I will call the guy at the john deer place who seemed to be very knowledgeable and who works on them for the dealer and see what he says also
 

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I worked for the local Stihl dealer for a while running his shop. All the newer saws spec 89 octane per the manual and the older saws spec'd 87. There was a service bulletin come across the bench that due to the addition of alcohol to 87 octane all equipment should be upgraded to 89 as it is not required to contain any alcohol and usually does not.

If you want a complete technical paper on alcohol and small carbs you should toddle over to the Walbro website and read the tech papers there. It is very enlightening reading and can even cure insomnia for those that don't really understand the basics of fuel induction.

You will be glad to pay a few cents more a gallon for 89 octane after the first piston and liner you get to purchase for your equipment. $300 is typical and can be higher. Alcohol actually leans the mixture and without boring the main jet the mixture just cannot be rich enough to prevent "Lean Burn" and pre-ignition resulting in melted pistons and scored cylinder walls.

An old thread I did a couple of years ago that shows how to test for alcohol in fuel.
http://www.mytractorforum.com/showthread.php?t=146217
 

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Discussion Starter #5
I worked for the local Stihl dealer for a while running his shop. All the newer saws spec 89 octane per the manual and the older saws spec'd 87. There was a service bulletin come across the bench that due to the addition of alcohol to 87 octane all equipment should be upgraded to 89 as it is not required to contain any alcohol and usually does not.

If you want a complete technical paper on alcohol and small carbs you should toddle over to the Walbro website and read the tech papers there. It is very enlightening reading and can even cure insomnia for those that don't really understand the basics of fuel induction.

You will be glad to pay a few cents more a gallon for 89 octane after the first piston and liner you get to purchase for your equipment. $300 is typical and can be higher. Alcohol actually leans the mixture and without boring the main jet the mixture just cannot be rich enough to prevent "Lean Burn" and pre-ignition resulting in melted pistons and scored cylinder walls.

An old thread I did a couple of years ago that shows how to test for alcohol in fuel.
http://www.mytractorforum.com/showthread.php?t=146217
yeah i guess i will just get enough of the 89 that i will need for the grass cutting period or rather get maybe a half a gallon at a time. I will monitor how quickly I use that up and go from there
 

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Run some cheap gas in a cut-off saw, where the engine can run at full load for an extended period of time, and you will be looking for a new cylinder kit due to detonation damage.
 

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Discussion Starter #8
yall keep saying saw but it's a weedeater lol. I guess same concept though probably.

I just called the place I bought it from, john deer and talked to the service guy and he said to run something without ethanol. I told him what the manual said and it said 89(R+M/2) or higher, didnt mention anything bout not running non ethanol unless the R+M/2 is non ethanol. He said if i run 89 midgrade with ethanol just run it wide open. He said the Stihl's are made to run wide open and that running wide open would assure nothing get's clogged up in there; the screen or anything.
 

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89 is quite often a mix of 87 and 91 or 93 octane blended at the pump so it will probably have less than 10% ethanol given that premium usually contains no ethanol. Some pumps have 10% in all 3 pumps so it pays to check.
 

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yall keep saying saw but it's a weedeater lol. I guess same concept though probably.

I just called the place I bought it from, john deer and talked to the service guy and he said to run something without ethanol. I told him what the manual said and it said 89(R+M/2) or higher, didnt mention anything bout not running non ethanol unless the R+M/2 is non ethanol. He said if i run 89 midgrade with ethanol just run it wide open. He said the Stihl's are made to run wide open and that running wide open would assure nothing get's clogged up in there; the screen or anything.
WOW- you need to stop getting advise from them, that is total garbage. Do you ever see the commercial mower guys running their weedwacker at max rpm all the time? No. Not needed.

Stihl knows there equipment, just follow the directions from Stihl.

Just stop being cheap and use the correct fuel. Better yet, use the premixed fuel available everywhere from Sears to Lowes to Walmart etc...
 

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Discussion Starter #11
WOW- you need to stop getting advise from them, that is total garbage. Do you ever see the commercial mower guys running their weedwacker at max rpm all the time? No. Not needed.

Stihl knows there equipment, just follow the directions from Stihl.

Just stop being cheap and use the correct fuel. Better yet, use the premixed fuel available everywhere from Sears to Lowes to Walmart etc...
lol man aint know way i was going to run it wide wide wide open constantly. Enough to get the job done thats for sure. So yeah it says run 89 and i will run that. Comes with a 2 yr warranty and for buying a 6 pack of oil for 12 bucks i got an extended 2 yrs for a total of 4 yrs so if it ****s up doing it how the manual says then it will get fixed
 

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My Stihl leaf blower calls for premium gas too. Been using it for 4 years now and it runs like a charm. Nothing broken,- not even my wallet. lol ! No sense in being penny wise and pound foolish in this caser.
 

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Discussion Starter #13
My Stihl leaf blower calls for premium gas too. Been using it for 4 years now and it runs like a charm. Nothing broken,- not even my wallet. lol ! No sense in being penny wise and pound foolish in this caser.
true and mine says nothing less than 89 mid grade R+M/2
 
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