If it is a stock carburetor and mostly stock saw, open the Low screw 1 turn and leave the High screw closed. Leaving the High screw closed will ensure that the High speed system is not effecting the Low speed adjustment. Start the saw and set the idle at 3,000 with the idle screw. Slowly turn in the low screw, what you are looking for is about a 200-250 RPM rise before the RPM falls off again. If the RPM rises more than that, then readjust the idle with the Low screw turned 3/4 turn out. If there is little to no rise while turning in the Low screw set the Low screw to 1 1/4 turns out and reset idle and recheck for RPM rise as you slowly screw in the Low screw. Note: with every Low screw adjustment you will need to reset the Idle RPM.
Once you have achieved a 200-250 RPM rise while turning in the Low screw move on to the High screw. Open the High screw 1 turn and check "wide open throttle" RPM. The MAX RPM for that saw Husqvarna publishes is 12,500 RPM. To increase the MAX RPM slowly turn in the High screw, to decrease the MAX RPM turn out the High screw.
There may be other successful ways to adjust the carburetor, but this is what works for me. Always adjust the Low screw and idle first as the Low jet continues to feed fuel at "wide open throttle", then move on to the High.
