Stihl string trimmer starts but won't run

IA Leo · Aug 5, 2011

This reliable FS85 has been an easy starter-until now. Starts, runs a few seconds dies, seems to need heavy choke to run at all. Cleaned the air filter, changed the gas, replacing it with more from same can. Ready to take to the dealer. Wondered if there was some easy fix?
Leo

Anonymous-0 · Aug 5, 2011

If it's got the fuel line that runs in the tank like the saws, it's most likely sucking air. My saw did the same thing, quick/cheap fix with a new fuel line.

GordoSD · Aug 5, 2011

crack or hole in fuel line

dpurvis1 · Aug 5, 2011

before you take it to a service man pull the muffler and try it. they get carboned up and then if it sits for a while unused it hardens and blocks the exhaust. many 2 cycle power tools have been discarded that didn"t need to be.

crotchity · Aug 5, 2011

Check exhaust for mud dobbers. They plugged mine and it acted like yours.

36F30 · Aug 5, 2011

Most Stihls have a spark arrestor screen in the muffler that plugs up. Take it out and pitch it

cole in mo. · Aug 5, 2011

if its not the muffler, and lots of hours useage, you may have to pull the carb, and remove the square plate that has the idle screw on it, under that is the needle valve. you don't gotta remove it, just use a very small screw driver, and lightly bend the tab attatched to the needle valve up just a little.

Anonymous-0 · Aug 5, 2011

As posted below, I'd check the lines for cracks. I'd also chuck the gas in your can, if it's over 30 days old. Also, there is a recall for gas caps, if yours doesn't have the indicator arrow, on it, both it and/or the tank could be bad.

Bob · Aug 5, 2011

"Wondered if there was some easy fix?"

YES! Roundup/glyphosate and a hand sprayer. NO more trimming/line/gas/oil/crap that won't run!

Anonymous-0 · Aug 5, 2011

I agree pitch the spark arrestor.
Check/clear fuel lines.
Try a higher octane fuel in the mix.

A new carb is $25.00 +/- Stihl bought (forgot the manufactures name).
Ultrasonic parts cleaner can sometimes get the orifices cleaned out that are gummed up. Careful with the compressed air. Parts will go a flying.

Get a goat.

Bryan inIowa · Aug 5, 2011

Stihl has had lot of carb troubles on trimmers . plastic check valve in passage that cannot be clean or replaced . Carb kit cost $29 . new carb $26 ,15 min labor and your good to go . no brainer. I have 2 5 gal pails of old Stihl carbs .

JDseller · Aug 5, 2011

Go get some fresh gas. WITHOUT ethanol in it. You are using the same gas that is in your trimmer. I only mix up a half gallon at a time anymore the shelf life is real short. You can spend a lot of money fixing something that is not broke. I would bet Stale fuel.

2x4 · Aug 6, 2011

try the muffler first. Take the nut out of the muffler. It is hollow so exhaust passes thru it. On the inside is a tubular screen. Take a screwdriver & push the screen back til it comes off the nut & as others say, toss it.

SJ · Aug 6, 2011

Mine had bees nest in the muffler,did the same thing.Never thought of looking in there I only looked in the intake.

Good Luck
Stan

eastexan · Aug 6, 2011

Sounds like it's starving for fuel.

First thing I'd do is replace the fuel filter. If the trimmers are like chain saws, it will probably be in the fuel tank on the end of a hose. Very easy to replace. Just use a little hook and fish it out.

Stihl string trimmer starts but won't run

IA Leo

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Anonymous-0

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GordoSD

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dpurvis1

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crotchity

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36F30

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cole in mo.

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Anonymous-0

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Bob

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Anonymous-0

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Bryan inIowa

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JDseller

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2x4

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SJ

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