The picture on the left is the Honda GX200 clone labeled Rui * Ing. On the right is an original Honda carb.
The clone carb has a shank comming out of the block with a top flat disk. Sticking out of the disk is a short stub. The stub is what is left after the square plastic cap is broken off. That part matches the pdf description. But the remainder won't unscrew. There's no threads or spring there. Possibly they have inserted a low idle jet and Locktited it in place.
The clone carb square cap matches the pdf description. The snapping off part matches the pdf description. The Honda original carb does not but it does have a threaded screw and a spring. The clone does not. The clone parts breakdown shows a screw and a spring.
Neither carb exactly matches the Honda pdf but the original does have a screw and spring. The clone appears to be non-adjustable. The local dealer is very helpful and today he gave me the Honda carb body to check out. He says he's never had to adjust a low idle.