Are you checking to see if your getting any hotspots on the coils? Try installing it without cotton and check if the coil gets hotter in specific areas and then pinch and strum the coil to fix that and then add the cotton. This could be your problem and its easily fixed.I just wrap another coil. I haven't bothered trying to fit that little coil back in that housing after clipping the leads short enough.
I thought I had a good one earlier, but I was getting a bad taste. I had a not so good coil in for a longer time than I should have last night and this morning before replacing it with said good coil. I was blaming the juice being turned bad from the coil so I wrapped another one. when I took out the one I thought was good after using it for a while, I was right. It was nicely saturated and not one bit dark anywhere. That's why I blamed the juice.
Thanks! Vape on