Vacuum lines and check valve system

[YZR500]

Can someone explain to me (in plain English) what these are and what are their purposes ?





This may sound like a dumb question for most, but I am having trouble finding out why is my supercharger is generating boost in burst and suddenly dropping. I am thinking of a leaks of some sort. The only place left for me to check is from the above picture where it is connected to my power pipe feeding into the throttle body.

The connection at #13 on the picture is where I am seeing a tremendous amount of vacuum, is this normal, because it is robbing all of the air my windmill is pushing,...

Thanks in advance for the help.

[YZR500]

I am surprise noone has an opinion on that one,...

Please, I am still looking for help in understanding the above diagram and components?

Especially the check valve (18) and the "y" piece (13) as well as the function of hose 14 connected in the driver side plenum.

Thanks

Stephan