Engine stalls.

As a complete newbie on carbs I googled to learn more. Some of pictures I found of the carburator the setup wasn´t like mine.

Mine has the vacuum hose plugged (A) and therefore not connected to the choke vacuum diaphragm (B).
But on the pictures I found on the net (A) is connected to (B).

Could that be the other – or the only reason – why the engine stalls?
I just want to ask before I start to check the float settings.