This is from a chainsaw service manual on the 49SP:
CARBURETOR. All models are equipped with a Tillotson diaphragm carburetor, Refer to Tillotson section of CARBURETOR SERVICE section for exploded view and overhaul of carburetor .
Initial carburetor adjustment is one turn open from a lightly seated position for both low and high speed mixture screws. Make final adjustment with engine warm and running. Adjust idle speed screw so engine idles just below clutch engagement speed. Adjust low speed mixture screw so engine will accelerate cleanly without hesitation . Adjust high speed mixture screw to obtain optimum performance under cutting load.
