Small Engines (Lawn Mowers, etc.): tuning question, spark arrester, carb adjustments

Question
QUESTION: hi. i have a stihl brush cutter its a fs-55c and im having a little trouble with the tuning. it runs fine its just when i give it alittle throttle it bogs down. and then sometimes it idles fine and other times it idles for alittle then shuts off.

ANSWER: Do you have limiter cap on the carbuetor ajustment needles?

See page 24 of the link below for carb adjustment.

http://www.stihlusa.com/stihl_ownersmanuals/FS75_Manual.pdf

This for an FS75, the FS55 manual has an error, but the FS75 carb adjustments are the same for each model.

Also see page 26 to make sure the spark arrestor is not clogged with carbon.

Let me know if this helps.
Eric

---------- FOLLOW-UP ----------

QUESTION: hi. i tried that link you gave me it didnt work so i went to shihls website and tried it same thing didnt work might be my computer. also what is a spark arrestor? thanks for your help.

Answer
The FS 55 link did not work for me but try any link, even the chain saw links will work for carb adjustment.

The spark arrester is in the muffler.  Stihl makes it easy to remove the spark arrestor for cleaning by just removing a couple of screws on the muffler.

How old is your trimmer?
Eric