I exchanged Adjusting Screw at the same time I exchanged carburetor for PC 20. I bought it because my friend's Motorcycle was easy to adjust and it seemed convenient. In actual use, the operability at the time of adjustment improved dramatically, the product itself was also well made and it became also Dress-up of Carburetor Body.
I bought it for Fashion purpose, but it is useful Parts.
Idling adjustment can be done without rushing tools when Idling changes on rainy days or high altitude where it is quite useful.
My car is CUB, so if you have a Leg shield you can use a fairly short Driver and you can not make adjustments unless you look into it from below, but you can adjust it by hand if there is this.