So I recently purchased a Smok Stick V8 with a big baby tank from someone who had changed the coil to a .15 double coil. It hits amazingly for the first 5 hits or so. Then it gets a burnt taste that is painful on your lungs. All my friends tell me that my coil is burnt, but the flavor is fine until I've been hitting off it a while. Than it takes about 5 hours to not taste burnt. Do I need a better coil? If so, what coil should I buy for the most extended use? If not, what should I do?