Protein Skimmer Impeller Not Rotating

[kennykimny]

Hello,

I have a Berlin Venturi Hang On Skimmer (just received it today), and it was very noisy so I disassembled the pump, and tried reseating the impeller. After trying to fiddle with it, I noticed that it was operating well (still noisy) for a bit, but then it it turning very very slowly. Is there a trick to reinstalling the impeller that I am missing? Thanks.