Is it a burnt taste? I too am vaping with the Nautilus mini tank and changed my coil out after about ten days. Still, I get the occasional "burnt" hit, even with a new atomizer. I notice that I especially get hit with the burnt taste when I haven't pulled a hit off of it in a while... Seems that the more often I hit it, the better it tastes... I am very new to vaping (and this is my first day here) so I am also looking for tips and trying to figure things out as I go... I'm always adjusting my port depending on how it's hitting...
When I purchased my e-cig two weeks ago, the guy at the shop suggested that I set my battery (Vision Spinner II) on 3.8v when using the Nautilus mini tank.. However, I have found that on a full charge, it hits better if I drop it to 3.3v, and as the battery starts to die down (under 30%), I'll crank it up to 4.3 or 4.8v... Not sure if this is just all in my head, but it seems to be helping with the burnt hits.. I too would welcome any suggestions.
The vision spinner is a regulated device, meaning that a computer chip inside controls how much power is actually going through the coils. The higher the power, the quicker the battery will drain, but it will put out what you set it to from a full charge until the battery dies. The same cannot be set for a mechanical (unregulated / no computer chip mod) because that will put out power proportional to how charged the battery actually is.
That said, how hot the coil gets will affect how consistently the juice wicks up the material, as will the level of juice in your tank. I don't know about the bvc coils (that come with the nautilus mini) but other bottom-fed coils tend to perform poorly when the juice level gets very low. When you push the heat up really high, it may be drying out the wick faster than it can keep getting saturated and this can and does lead to more burning.
Another thing to consider is the ratio of vg to pg in the juice you are buying. I'm guessing you have 50/50 juice, since that's generally recommended for beginners. The more pg, the more flavor you will get, the harsher the throat hit will be, and the easier the juice will wick up, ensuring that it is always saturated so that the coals aren't heating up dried-out wicks and burning it. More vg will give you a smoother vape and bigger clouds, however, so it is more appropriate for a rebuildable dripper type atomizer.
The biggest advice I can give you, especially for the nautilus, is to let the tank sit for a minute or so before going to use it right away after you put a new one in, and more importantly to take a few primer puffs (don't power it) which will help the wick saturate with juice. If you hit the vape too soon, it may burn the wick a little bit right before it fully saturates, which will burn it very slightly and then leave a somewhat permanent taste that does get lesser as you keep hitting it. This also applies to when you leave the vape alone for a while, some of the juice will leave the wicks and you'll experience the same problem. Both of these scenarios seem in-line with what you're describing.
So give that a try, and I hope that helps!
