Dear your understanding is different pls read carefully again the statement written on the page # 23:
Rotate handle left to decrease air flux, choke is in close condition and mixed gas conscentration incresed, which makes the vehicle is easy to start. Return to right to increase air flux and choke is in open condition. Release the choke handle bar after the engine is warm up.
In this paragraph discussed handle bar is concerned with choke lever not the steering/handle. (pls use choke lever instead of handle bar in above atatement its typing mistake in the book due to translation by Piaggio people)
I think u understand now, pls consult wth me before u highly announce any thing;)