Remove the screw in the handle, located on the bottom rear then remove the throttle rod from the trigger.
Clean the crud that collects in there while you have it apart.
The WT 22 and the 194 are cheap and easy to rebuild. Both are made by Walbro which can be bought from many sources for 50 to 60 bucks if you want a new one.
The rebuild kit is the same for both carbs i think. WAT-20 is the #, it's late so thinking is optional but that kit will do most of the WT carbs.