glad to hear you got the problem fixed.
agree!!
don't have a stihl, but the walbro carb on my husqvarna has an air bleed. air bleeds, just adjust the point where idle/main transition take place is all i know. this is based on air velocity. air flow is a relative term i guess, based on total volume.
is the richer (fuel) adjustment necessary based on?
a. air velocity
b. air flow (volume)
c. the altering (opening up) of the muffler which lessens the 'supercharging' effect of the back-wave as shown at the bottom of page here:
2 STROKE Guide to Wisdom
i say "c".....and a very sharp chain.
-OMB