# Stihl FS80R problems



## rango (May 21, 2014)

hello-new here- sorry for posting in a few places prior to figuring new thread creation out...

anyway-my fs80r wont start. got it to run for 15min, trimmed a little then it starting a viscious cycle of run/die, etc... now wont do anything. drained gas, ran seafoam mixed in with fuel, start, die, . cleaned carb, the little carb screen - which all was squeaky clean - repeat the new gas mixture minus seafoam. now nothing. ive had this thing since 2005 or 2006 didnt use that much- a few times /year (previous residential neighborhood had own lawn service).
it looks like brand new. so the question here is WTH is wrong??? why wont it start and stay running?
on the carb -how do i know which model carb i have if i have to get a new one or rebuild kit/gaskets?
and is it possible that the spark arrestor is clogged causing this? I havent looked at that yet but did see a youtube on it. the gas lines look good but are they glued to the carb inlets bc i was going to replace but they would not budge.

any suggestions/help would be appreciated!


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## XSKIER (May 22, 2014)

The carb model should be stamped on the side of the carb, otherwise a dealer can get you the correct parts by machine serial number. I would replace the lines, filters, spark plug, and rebuild the carb with new parts. If that fails, then pressure test to see if there are any air leaks in the engine or intake tract.


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## lewis16 (Jun 7, 2014)

Pull the plug and see if it's fouled, run a wire brush over it and check the gap. 


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## LowVolt (Jun 22, 2014)

A new carb for these models is very inexpensive from the dealer. I think they are under $25 including tax. The fs80r is a great trimmer and well worth the time to fix.


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## lewis16 (Jun 23, 2014)

Might also be a good idea to try and find a solid shaft for one too. eBay might be worth a shot for that. Makes it a lot more stable if you wish to use a blade. Also allows you to put a hedge cutter head or a chainsaw pruning attachment in place of the trimming head. Essentially you then have a long reach hedge cutter or a pole saw. 


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## chainsawman2011 (Jul 1, 2014)

yes like lowvolt said get a new carb. yes they are only $25 around here anyway. those carbs on those are not worth time or money to rebuild because half the time it is the actual aluminum in the carb somewhere that is the problem from ethanol.I would also make sure u are getting consistent spark. these machines have a habit of having bad coils although I have have owned an fs80 from new in 2002. still orginal coil and carb lol


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## lewis16 (Jul 3, 2014)

Yeah mine was really iffy when I first got it. I was given it from doing some work and wen I got it the carb was set really quite oddly. Wouldn't run right so the plug was fine and have a good spark, the points were fine, it was getting fuel and getting air and compression felt good enough for government work so all it needed was carb adjustment. 


I have found a major drawback with the FS80 and that's the flexible driveshaft it uses, don't out a blade on unless it's the 2 bladed brush knife or it will judder and vibrate like nothing else you've e ever seen. 


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