# stihl FS 80



## nwhannah29 (May 1, 2012)

I know this question has been asked before but here goes again.

My FS 80 wi crank and run for a while then bog down and quit. What do you think is the problem? Here is a list of things I have done.

1. Rebuilt carb after cleaning multiple times.
2. New coil.
3 New fuel tank and lines.
i use 50:1 mixture with stihl oil.
i try to keep fuel treatment in the tank.

After I put the carb kit on it ran the best it has in a long time, but still got hot and quit. Should I mix the oil a little richer? 

I tried to loosen the cap and run it but that didn't seem to help. 

What do y'all think?


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## geogrubb (Jul 28, 2006)

nwhannah29 said:


> I know this question has been asked before but here goes again.
> 
> My FS 80 wi crank and run for a while then bog down and quit. What do you think is the problem? Here is a list of things I have done.
> 
> ...


It should have a zama carb, go to the zama site and check their tech info, they have some good infor. Have a good one. Geo
http://www.zamacarb.com/


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## dawgpile (Apr 28, 2008)

Take a look at the Stihl oil you use. Most of them have fuel stabilizer in them already. If so, don't add any more. Not the source of your problem, but not needed. I would not richen up the mixture. Use the specified ratio OR if the Stihl oil you are using is synthetic, then you can mix it 50:1 and use for any specified ratio from 16:1 to 50:1.

Did you replace the fuel filter in the tank? How long does it run before stalling out? ... seconds...minutes?

Let us know!


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## usmcgrunt (Sep 16, 2007)

Have you pulled out the spark arrestor screen on the muffler to check if it is clogged up? To much back pressure will cause an engine to over heat.


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## nwhannah29 (May 1, 2012)

The spark arrestor is gone. I am going to remove the muffler to see if I see any build up there. It ran great for 15 minutes or so now it will crank and idle fine but will not accelerate


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## jcsmith (Oct 9, 2011)

*fs-80*

I'm thinking it may be running too lean. Does it have a TK carb . If so, the 2 adjustment are not high and low . 3 actually, idle speed,air and fuel. The air screw only needs opening if running too rich. Better too rich than too lean. Let us know how you make out. . For some reason I thought you might be working on the old style FS80, the made in Japan one. Hope you got it running


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