The secondary air baffle on those carbs operates strictly by airflow / vacuum. There is no spring or any other way to adjust the opening other than to remove it and physically alter it. DON'T DO THAT.
There are no metering rods on the secondaries either. Fuel delivery is changed by jet changes.
I've found that many times what is offered in the calibration kits isn't what is need and end up buying a couple of different rod sets that are in the range I know from experience should work. Every engine is different and they will all take some patience setting them up. Just write down each change and after driving it make a note as to what got better and what got worse. This will give you a road map to follow as you go along. Sounds like this is what you're doing.
