Jacuzzi Skimmer Operations

I can't for the life of me figure out how to get my skimmer to have a 50/50 mix between MD and skimmer. I tried yesterday by moving the trimmer plate to have both ports open wide open. I then turned the pump back on and dropped the vac plate in as I was instructed. It seemed to be working, until a vortex was created, sucking air back to the pump. I believe I am missing some parts such as the weir. There are a few pictures below: First one is inside the skimmer. Second one is a exploded view of the skimmer (what is circled in red is what I don't have). Now you guys give me your synopsis. Thanks