Pot still huffing

[Stinky2013]

I have quarter keg with 2" to a reducer to 1" and a 3/4 water jacket with 1/2 in inner pipe. Cold faucet water in bucket with small pond pump flowing bottom to top. Question is I get a lot of air huffing out the end and I read to pack the arm at the top with some scrubber. But no matter how high the heat is or low it doesn't really stop. Is my water flow to high? Or to cold? Does this effect the output? New build used to use stove top with worm. Any help would be great thanks.