# Stihl FS56 RC Carburetor Adjustment Assistance



## kennykenny (Sep 23, 2007)

I have a Stihl FS56 RC trimmer. The unit starts up fine but will not idle when the throttle is let off, it dies pretty quickly. I am not clear on how to adjust the carb. in order to correct this. Assistance would be appreciated. Thank you.


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## Missouri Bound (Apr 9, 2011)

What you describe is a carburetor that is dirty.
How old is the trimmer? What grade of fuel do you use?
These small engines are notorious for running poorly when dirt is introduced into the fuel system. What I am saying is that it is most likely not an adjustment issue.
How mechanically inclined are you?


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## kennykenny (Sep 23, 2007)

Missouri Bound said:


> What you describe is a carburetor that is dirty.
> How old is the trimmer? What grade of fuel do you use?
> These small engines are notorious for running poorly when dirt is introduced into the fuel system. What I am saying is that it is most likely not an adjustment issue.
> How mechanically inclined are you?


How old the unit is, I'm not sure. I acquired it. I'm guessing around 10 years old(?). 

I am fairly mechanically inclined. At least I like to think so. Thanks.


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## Missouri Bound (Apr 9, 2011)

Dump out the fuel, change the fuel lines and filter.
If you have the ability, take the carburetor off and clean it, blow it out and re-assemble it with new gaskets. Pick up a manual for that model. That will tell you how the adjustments work. If none of that works, get a new carburetor....maybe Ebay or Amazon. If you take it to a Stihl dealer.....it will cost you more than you could imagine. You have a few options. But since you initial cost is "acquired" then you can throw a few bucks into it.
These little engines are finicky.....keep that in mind.


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## joecaption (Nov 30, 2011)

No way would I suggest trying to take the carb, apart and trying to rebuild it if that's what it turns out to be.
I'd just order a new one on Ebay, some come with the carb, air and fuel filer, spark plug and new fuel lines, cost about $13.00 with free shipping.


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## Dave Sal (Dec 20, 2012)

Get some Mechanic in a Bottle and add this to fresh fuel. Operate the trimmer as usual and over time this stuff will clean out the fuel lines / carburetor and it should run better.


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## Drachenfire (Jun 6, 2017)

I have a Stihl FS56 I bought about 4-years ago.

From day one I have used nothing but TruFuel. (Same with my Echo leaf blower)

TruFuel is ready-to-use fuel made specifically for 2-cycle and 4-cycle outdoor power equipment. It is precision mixed using 92-octane ethanol-free fuel and synthetic oil with stabilizers. It is available at big box stores in 50:1(red), 40:1(green) and 4-cycle (gray).

I have never had any trouble, starting, running or with power.

A $6 32oz container normally lasts me a season.


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## Missouri Bound (Apr 9, 2011)

joecaption said:


> https://www.youtube.com/watch?v=gmhxTvGRtCg
> 
> No way would I suggest trying to take the carb, apart and trying to rebuild it if that's what it turns out to be.


That isn't what I was suggesting. Removing two screws allows the carburetor to be removed. Much easier to clean, blow out, etc. if it's off the machine. As you said, it's not worth it to try to rebuild it with so many cheap knock offs available.
But replacing the carb isn't the whole issue. The fuel lines should be changed along with the filter in the tank. If you can do this, great.
As far as replacing the carburetor with one off of Ebay or Amazon.....it is most likely 2-3 times cheaper....perhaps more to do that than to take it to a shop.


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## kennykenny (Sep 23, 2007)

Looking on the internet for carburetors if I decide to go that direction. So many out there. I see listed many that say it fits Stihl FS55 not Stihl FS56 RC. is there a difference?


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## Missouri Bound (Apr 9, 2011)

You should be able to get a model # off of the carb. I believe those units use Zama carburetors.


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## Missouri Bound (Apr 9, 2011)

You can find the manual for your trimmer on the Stihl website.
They explain how to adjust the carburetor. Perhaps do that first before buying one, after you clean out the fuel tank and replace the filter and hoses.
And the RC designation just refers to the handle style.


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## Corey Poirier (9 mo ago)

kennykenny said:


> I have a Stihl FS56 RC trimmer. The unit starts up fine but will not idle when the throttle is let off, it dies pretty quickly. I am not clear on how to adjust the carb. in order to correct this. Assistance would be appreciated. Thank you.


my boss had the same thing happen to him bought a Stihl trimmer bran new and as soon as you let it idle would shut off took it to me I adjusted the idle screw up just a tad and it idle normal but if you do decide to adjust it be carful not to adjust the wrong screw There a high and beside there’s a low screw if you touch those with out knowing how to set them the trimmer will defently run rough or not run at all cause that’s your mixture but there should be a screw by it’s self which would be the idle that’s very easy to adjust which is labeled LA so my advice do what I told you before you go and spend all kinds of money on carb cliner and you would have to spend more money on buying a card kit if you took the carburetor apart


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## lenaitch (Feb 10, 2014)

It could be something as simple as the idle stop screw needs adjusting.


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