I have a FS55 and with all the bordem from social distancing decided to do some work on my yard equipment. Changed the carb, filters, fuel lines etc, spark plug and ignition coil. I am able to get the unit to fire up and run at full throttle but when I let off it will die. When I put a little pressure(has a little play in it)on the black curved tensioner piece that holds the throttle cable behind the carb I can get it to idle. I have also screwed in the hex head screw that is supposed to apply tension to the throttle cable. I have played with the high, low and idle screw at nauseam and can’t get it to stay running unless I am on the throttle. Please assist as my arm is tired and at wits end. Thank you!
#2
Fish
With the engine not running, watch the trimmer head when you pull the starter rope, it should not turn.
On my fs 55 stihl string trimmer, I cannot get it to idle either. My question is that when I take out the low speed adjustment screw, the engine should not run at all should it?
That will depend on how far out of adjustment the throttle stop and High speed jet are.
I regularly get trimmers & chainsaws in the workshop where the L jet is totally blocked & the engine is running on the H jet all the time
They will work fine like that except they are difficult to start & tend to stall when you let the trigger off quickly.
Both Zama & Walbro have nice colour diagrams of exactly how the carbs work at different speeds.
