# Stihl FS80av carb-I'm pulling my hair out



## griffin1854 (Nov 5, 2009)

I have just been given one of these as a non runner, and have thoroughly cleaned the carb.
I noticed the needle (TK slide valve, 3 screw carb) was slightly bent, and gingerly straightened it. alongside lots of other trial and error things.

The engine now starts.I have read previous posts and have the middle screw all the way in, and the other two at 1 - 2 turns out.

It starts when choked, and then immediately moving the choke off increses the revs to a usable level. When I open the throttle the engine bogs down, and unless release it stalls.

What are my next steps to getting this running sweet please.

I'm only a beginner, and am using this as a project to increase my knowledge


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## griffin1854 (Nov 5, 2009)

Also, what spark plug should be in it.Just want to check it is the correct one.


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## rotti1968 (Apr 26, 2009)

griffin1854 said:


> Also, what spark plug should be in it.Just want to check it is the correct one.


ngk bmr6a is what you need for the plug


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## 30yearTech (Sep 14, 2006)

The silver colored screw with the knurled edge is the idle stop screw, the larger brass colored screw is the high speed and the smaller one is the air bleed screw. The air bleed screw should be screwed all the way in. Try 2 turns out from seat on the high speed and see if it will run.


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## griffin1854 (Nov 5, 2009)

Thank you for the responses, I will try adjusting the high speed, and report back.

As I said, I am a novice at this, would an incorrect spark plug cause the problems I am experiencing? Also I am using fuel that was already in it, would a richer/leaner mix also cause these?


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## hdman97 (May 25, 2006)

try some fresh fuel with the correct mix,who knows how old the fuel in it is. 
I don't think the spark plug would give you this kind of problem.


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