In any tinkering with saws first thing I do is put in a new corrected and tested spark plug.
Helps get some parameters out of head.
One system at the time, if its not OK, go thru all of it part by part.
Start in one end and go thru all of system.
If its fuel system you start in tank with pickup/filter, then fuel line, carb, intake, impulsline etc..
Coffey help you a bit.. Education ladder is set pretty steep at first.
Being a cranky, stubborn old bastard that never give a inch also help in this work.
I have saws with 40hrs+ in them until I got them good.
But there is not much that beat the satisfaction you get when its running right, better than new even.
Keep in there and don't let a little inanimate thing as a saw get under your skin.