Suzuki 2 Strokes

I've dismantled the BS carbs for cleaning. The left side carb butterfly is very tight. I tried some PB Blaster which freed it up slightly, but it is nowhere near as free as it should be. I am facing dismantling the butterfly and removing the shaft, then a thorough cleaning. Looking at some previous posts I believe there are some o-rings in there. Anything else I should be aware of before I proceed?

Dont do that yet, try a few dabs of fine valve grinding paste mixed with WD40. Drop it onto the shaft interior by the butterfly valve and work the shaft back and forth, then flush it with WD40 followed by gasoline. Repeat as necessary until its free.
I try not to move those screws on the butterfly as they are staked on the back and you cannot recreate that feature once you move them.

Looks like problem is solved. I sealed off the mouth of the carb and poured in some PB Blaster, just enough to cover the butterfly. Left it overnight. Would you believe it the butterfly is now totally free!