A message to the original poster:
I have the same experience as you (I think).
I can only get two drops into the cart even after a full hour of puffing, the vapor comes out in giant flavorless clouds with no substance at all.
I have a weird question for you, do you get a "foamy" feeling from the vapor? Like it's doing something weird to your saliva? I get this experience when I start getting that dry vapor. The first few drags of a fresh cart are great, but then comes the nasty cloud of death.
I've read through this thread, and so far I see no new info as to what can be done to remedy this. I've tried all the standard maintenance stuff and still both attys give the same dry foamy vapor.
One of my atomizers started to unravel, the brown wicking from inside started to come out, getting tangled up in the bridge. I'm getting a replacement soon, if it works better I'll let you know. I sure hope it does, as I am going through 10 ml a day with the constant topping off. Too bad, as the first day or so with this thing it was rocking my world, but now...

I'm not giving up hope yet.
Edit: Could it be the juice I'm using? Has anyone else ever experienced this dry "foamy" vapor I'm talking about on a 510 or any other device? I hope it's the liquid and not the Yeti, as that would save me a few bucks when it comes to replacing stuff.