Im surprised so many of you are having issues with the killer. I got it a couple weeks ago, filled it with juice, primed it and its still rocking today. I think the most important part is putting the bottom cap on and creating a seal. There will be a bit of pressure in there so when you open the juice control, it will force juice in to the killer. Another thing is to make sure the ceramic cup (middle piece) is tightly screwed on to the top piece that you attach the drop tip to. Only lightly tighten the 510 piece to the bottom of the ceramic cup part. Otherwise, when you assemble it and attempt to open the juice control, the whole thing will spin and you'll have to disassemble. An easy way to adjust the juice control is to hold the bottom end cap and spin the tank counter clock-wise. This way, the only thing that moves is the opening of the juice control.
Hopefully everyone will be able to enjoy this amazing piece as much as i do!
I agree with what you said but with the Phiniac tanks the inner orings are so tight that you can't turn the juice control, at least I can't, that's why I leave it open before I snap the caps together. I haven't had any problems doing it this way. Maybe other tanks don't have such tight orings.