Just got some Kanger 510 cartos from LF, and after filling, which was easy, I get five or six really good blasts, but then they start to burn dry. I've tried two of the five, and they are both the same. I can saturate them, so I get liquid in my mouth and it comes out the bottom when putting the bung in, but still a really short time before I get the burning taste. Am I missing something, or are these just not that good?