I use those Smoktech 1.7 ohm cartos from CCV all the time and have only had one bad one. I have every size available. I'm not as fond of the jumbo xxl ones like I thought I would be. But, the shorties, standard and XL's have been great. Though, if you are hitting it constantly chain vaping, you are going to dry it up rather quickly and may be burning it enough that it's not wicking the juice properly. Cartomizers need some time between hits for the juice to readjust/rewick itself in the wadding. You may need to slow down a little and give it some times between puffs. Carto/tanks are wonderful things, if you want to get away from topping off. (I also refill my cartos using the condom method rather than dripping into the top....well, except for the shorties)
The only other thing I can think of is if you are using a really thick juice in them. I have no problem with Alien Visions juices, Heather's Heavenly Vapes, Virgin Vapers juices in mine. They are all 100% VG juices but are thinner than straight 100% VG. If you are using something that is really thick, you could run into even more problems with wicking.
