av8tor, I agree completely with you regarding the use of carb cleaner on our small carbs. I hear it recommended all the time but in personal use, I have seen it destroy rubber parts so I avoid it completely. Most of our smaller carbs use a simple capillary screen arrangement for a HS check valve but many of the larger carbs use a rubber valve held in place with a spring, all assembled in a brass housing. If the rubber valve gets damaged the carb will no longer function w/o replacing the valve. Some of our smaller WT carbs also have this rubber checkvalve so caution should be exercised. Carbs with accelerator pumps also use check valves but few of our carbs use these pumps. A carb with a plugged or damaged HS check valve may idle nicely but not transition to full throttle. If it is just damaged, the engine may run at full throttle but require the HS needle be farther out than normal.
These days in place of carb cleaner, I use electronic parts cleaner in a spray can which does not damage rubber or plastic but still has excellent solvent properties.