Stihl MS170 running like crap

[DonaldRobertson]

I know some of you may have experienced problems like this before but a few days ago I took my saw out of winter storage and cut down a tree but the thing is I used gas that I had from the summer of last year and after about 30 minutes of running the saw with the gas from last year I started losing power. I heard this is caused by the carburetor getting gummed up and my dad mentioned that if I buy the carburetor gum out cleaner that it will take like 3 gallons of gas before it really takes effect to clean it all out. What do you guys think of this and could this be the real problem to this. I bought the saw and the gas that I used the other day back in like August 2009. Let me know what you guys all think.

 

[treedoclang]

Try running a tank of fresh mixed gas through it. It's probably the old gas that is causing the problems. Gas that is more than a month old begins to break down and turn to varnish. This old gas will make any engine run poorly. Check with a local small engine repair facility that you trust and find out what gas station they get their gas from. The amount of ethanol in the gas varies from brand to brand and you want the least amount of ethanol. Hope this helps.

 

[Daniel]

did you give the gas a shake to mix it up? the oil might have seperated and sunk... a friend bought a used 66 in great shape and blew the piston on the first tank, cause he didn't change the gas and it had been sitting..

 

[DonaldRobertson]

Yeah, I shook the gas up really good.

 

[classictruckman]

If the new gas doesn't help you might check the spark arrestor in the muffler, it may be gummed up from the old gas too.