Stihl MS171 chainsaw will not start this season?

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
I don't trust Stihl Ultra at all. Too many pro users have reported problems with it.

The Husqvarna XP+ full synthetic is a good 2-cycle oil is a JASO FD rated oil. The Echo Red Armor that @qwee mentioned is also good (and also FD rated).

I run 50:1 in all my saws using Husqvarna XP oil for the past 10 -12 years years (since about a year after it first came out) without a problem. I've never found a need to to run a mixture other than what the saw manufacturers recommend, and have had good life out of all of my saws. It do run only ethanol-free gas in my small engines. I do also pay attention to how old my mix is. When it gets to old, it gets dumped in my antique truck, which will run on just about anything. The canned stuff is just too expensive for me to consider, especially since I'm getting good results without it. If I were only running small amounts and my saws tended to sit for a long time, I'd probably consider it.
Where do you get ethanol free gas? They use it now to adjust the octane too as well as create a market for corn. The Av gas has lead in it I believe and you can't buy it. Like you say the canned gas is good but expensive. I bought a new saw and still on the first can of 40:1 and unless I need to run it on a big job, I'm never putting Eth gas in it.
 
Where do you get ethanol free gas? They use it now to adjust the octane too as well as create a market for corn. The Av gas has lead in it I believe and you can't buy it. Like you say the canned gas is good but expensive. I bought a new saw and still on the first can of 40:1 and unless I need to run it on a big job, I'm never putting Eth gas in it.

Ethanol does add a bit to the octane rating: for E10 gas (10% ethanol) generally about 2 points, so an 89 octane E10 gas would be about 87 octane if you took the ethanol out.

Access to ethanol free gas varies from state to state in the US. For example, it's easy to find in Vermont - usually just as 91 octne at most stations. however, it can be very tough in Massachusetts (usually the only way to get it there is by purchasing canned gas). I'm not sure about availability in Canada. When I'm away from the know stations near home that carry it at the pump, I visit pure-gas.org. It's a user-supported website that lists sources of ethanol-free gas in the US and Canada by state or province. Unfortunately, it also sometimes includes sources which just sell canned gas, so it can take a bit of work to determine where the pump gas can be found. (Often, reading the descriptions or comments on an individual station will give you a clue.)
 
Ethanol does add a bit to the octane rating: for E10 gas (10% ethanol) generally about 2 points, so an 89 octane E10 gas would be about 87 octane if you took the ethanol out.

Access to ethanol free gas varies from state to state in the US. For example, it's easy to find in Vermont - usually just as 91 octne at most stations. however, it can be very tough in Massachusetts (usually the only way to get it there is by purchasing canned gas). I'm not sure about availability in Canada. When I'm away from the know stations near home that carry it at the pump, I visit pure-gas.org. It's a user-supported website that lists sources of ethanol-free gas in the US and Canada by state or province. Unfortunately, it also sometimes includes sources which just sell canned gas, so it can take a bit of work to determine where the pump gas can be found. (Often, reading the descriptions or comments on an individual station will give you a clue.)
They passed a law in Canada that forces them to add it. I guess to make food more expensive, although today's corn is probably garbage compared to what they had in Mexico 2000 years ago. I tried that Website and it was of no help as they are supposed to have added it here. I have only one pump Petro Canada, that does not have the Ethanol label, but that could just be because they are too lazy to put the sticker on the pump.
 
They passed a law in Canada that forces them to add it. I guess to make food more expensive, although today's corn is probably garbage compared to what they had in Mexico 2000 years ago. I tried that Website and it was of no help as they are supposed to have added it here. I have only one pump Petro Canada, that does not have the Ethanol label, but that could just be because they are too lazy to put the sticker on the pump.
I suspect you are right, and they have just not bothered to label it. If you are curious, there is a very simple test:

  • Find a clear container taller than it is wide (an empty coke bottle with the paper label removed so you can see the fluid inside works in a pinch)
  • Draw a line with a permanent marker about an inch or 3 cm or so from the bottom.
  • Fill container with water up to the line you drew
  • Add fuel up to about 80% full
  • cap and shake well
  • let settle for a few minutes
  • the water will settle out and be visible as a separate sort of "bubble" at the bottom of the container. If there is ethanol in the fuel, it will combine with the water as well. If that "bubble" at the bottom is above the line you drew, that is the ethanol that has now settled out of the fuel with the water. The mount above the line is the amount of ethanol that was in the fuel. (It may not hve removed 100% of the ethanol, but it does pull out the vast majority of it.)
 
  • Like
Reactions: Whitenuckler
I don't trust Stihl Ultra at all. Too many pro users have reported problems with it.

The Husqvarna XP+ full synthetic is a good 2-cycle oil is a JASO FD rated oil. The Echo Red Armor that @qwee mentioned is also good (and also FD rated).

I run 50:1 in all my saws using Husqvarna XP oil for the past 10 -12 years years (since about a year after it first came out) without a problem. I've never found a need to to run a mixture other than what the saw manufacturers recommend, and have had good life out of all of my saws. It do run only ethanol-free gas in my small engines. I do also pay attention to how old my mix is. When it gets to old, it gets dumped in my antique truck, which will run on just about anything. The canned stuff is just too expensive for me to consider, especially since I'm getting good results without it. If I were only running small amounts and my saws tended to sit for a long time, I'd probably consider it.
Do you make sure your saws are full up on oil every time you use one? I think that would be a good thing I should do?