# Help with Stihl FS55-R idle adjust? need help please.



## treepete (May 8, 2014)

Hi my name is Pete, and I’m new to the forum. I’m looking for help on my Stihl FS-55R line trimmer.
After 3 years of faithful service and very limited maintenance, my trimmer is giving me grief this year.
I have fresh gas, new plug, cleaned the air filter nicely, and the muffler is unobstructed.
I can get the machine to start properly but cannot get it to achieve significant speed to actually trim any grass. I have restored the H,L and idle needles to their factory positions and tried small tweaks on the low to improve the performance.
After trying all different configurations/settings etc on the needles I think maybe something else could be wrong? This is why I am here, to get more ideas of what to check.
The trimmer idles great. When I throttle it (gradually or suddenly) it bogs, but does not kill. When I adjust the low needle and lean it out, there is no change in the performance, and when I lean and lean it out more until the needle closes, then it will kill.
The fuel filter is clean I see it inside the tank and it looks new. Gas mix is correct ratio and is fresh. Plug is new, and not getting dirty or fouled.
Some other things I thought I would mention .. the machine shudders a bit on early throttle.... maybe rotational forces are at play with the clutch(?) area inside where I cannot see very well. it makes a bell-sound or ringing sound, but can spin freely when I stick a screwdriver through the grate (obviously when the unit is off, not running) It did this shaking last year also, but once up to speed it found a sweet spot and did not resonate/vibrate. Like a shaky tire on the car, only vibrates at 25mph, but not at 55mph etc.
Fuel seems to flow properly at idle.. needle tips aren’t dirty or corroded… but nothing is changing when I adjust the L needle. 
The H needle has only ¾ turn of total adjustment, and that didn’t seem to do anything either so I left that as is. I have idle speed needle set that the cutter head does not turn at idle.
Should I take it all the way apart and clean everything, or am I overlooking something like.. maybe it wont spool up due to load or something wrong with the clutch>?

I'm stumped. 
I hope someone can help me get on the right track of troubleshooting.
Thanks in advance for your thoughts,
Pete


----------



## treepete (May 8, 2014)

OK gave the machine a super deep clean. Carb, new-new fuel filter, double-new plug, total disassemble carb, blow-out awesomeness, spotless. Glorious, clean, pure, factory-new perfection.


Thing still wont start.





thought about it... checked muffler, spark arrester was totally clogged. Washed it with gas, a wire brush and a toothpick,... instant 500 horsepower.

Thanks everyone.


----------

