AquaC EV-120 Setup

I recently bought a used AquaC EV-120 that came with a Triton 3 pump. I have had it setup and running for a few days now and it doesn't look like much is happening in the skimmer neck. I have the air valve and gate valve all the way open. SO... here is the question, could it be that this Triton 3 is too powerful for this skimmer? This pump is rated at 850gph of unrestricted flow. The skimmer calls for somewhere around 550gph. If I close the gate valve at all, it rapidly starts pushing water up through the neck and if I close it about half way, it starts shooting water out the air valve and overflowing. This model also has the JG speedfit but I dont have anything in it. Should I plug this up?