Skimmer Problem...Please help.

[GreenSpottedPuffer]

Wondering if this could be a problem...I bought this skimmer used from a member here and it was modded a bit, so I do not know exactly how it came from the manufacturer. One thing I have noticed when I look at pics of beckett heads is that when you take them apart, they have a few rings that hold then pieces together like in the pic below...Mine does not have these. Not sure if thats anything but I am sooooo lost right now on why thing thing is not working.