Dry burns are not good for Protank 2
coils. By dry burning them, the little rubber plug that goes in under the coil can easily get burnt. If that happens, you'll get a burnt taste. Sorry, but that's just the way it is. And I've noticed that some of those little rubber plugs are really not good quality compared to others.
Instead of dry burning, simply rinse it under a hot tap, soak it in hot distilled water for a couple of minutes, or anything else that's been recommended on ECF. Leave out over night, resemble the next day.
Another thing for the burnt taste,
just don't go too high on volts. It isn't always needed. People tend to want to crank up the volts as quick they can before they've even tried 3.7v, and wonder where the burnt taste is coming from.
I can assure you, with my PTII, 2.4Ω coil, the tinniest two cotton wicks, 3.7v setting, there is absolutely no need to go higher. The flavor and the vaper production is out of this world.
A note for newbies:
Getting what you want is not by more power alone.
I understand the desire for more power, flavor and vaper production. That seems to be what many people want. But getting everything just right is actually a delicate and learned art. Assembling the Tank correctly, understanding the personality of any given tank, the coil, the wick, the air holes, the ohms, the volts, how long the battery is fired for, the draw, the liquid itself. All these things take time to learn how to best be put together.