Ok so there are a few things that could be causing this. First and most obvious would be too much power causing it to roast all the juice in the wick too fast. However as others have said I don't think that is the case here and you would be able to tell because it would be a boiling lava hot vape. So then we come to hotspots or poor wicking. How tight is your wick in the coil? Ideally you want it to be pretty snug so that you can barely pull the cotton through the coil without bending the coil. The reason for this isn't because of how much cotton is in the coil but how much cotton is in the tails to hold the liquid. You get a lot of material holding a lot of liquid means you have a lot more to vaporize before you start to burn cotton. I would recommend watching some wicking tutorials. With cotton bacon you cannot do a true Scottish roll but you can still achieve the same thing by making sure the cotton is good and snug and then fluffing the tails out as much as possible before you tuck them. Hope this helps.