“Gurgling Spitting and Popping”
This is because of excess e-juice getting past the coil due to the pressure differential of inside your tank as you vape.
To fix: Remove the drip tip, wrap some tissue, paper towel, over the end. While FIRMLY
holding your setup (tank away from you), forcefully flick several times. Be sure not to lose your grip and send your setup flying across the room!!! You should see some liquid on the tissue. Wipe out the area where the drip tip goes, replace the drip tip and continue vaping.
Watch the following video for further explanation and demonstration: Quick Fix to Gurgling in Vape Tanks (YouTube)
Preventing: Increase the voltage/wattage and/or use a larger air hole. Also, draw on the tip at the same time as pressing the battery firing button. Do NOT press the firing button, then draw on the tip.