Nice tutorial Sir!
There is also another adjuster on the grip end of the cable. It is either a barrel, and lock nut after the 90* bend or the 90* bend itself can be spun out a turn or two, and its lock nut tightened. The later method requires taking the cable off the carb, and pulling it free of the frame.
I only mention this because as you pointed out... you are right at the end of the threads on the carb end, and I could tell from the way you "settled" you would have liked another 2-3mm less slack.
My guess is the barrel adjuster is loose, (throttle end) and that's where all the slack came from.
Vivo... Philli bikes have Hamster cages, and all the engine stuff doesn't apply there. Sorry Bro!