I bought the limitless XL tank let's say sometime is October. I was always jumping between the 1 and 2 coil build decks and the prebuilt C4 coil. Recently I haven't been wanting to build so I bought some new C4 coils and I've always vaped the c4s between 90 to 120 watts. The last two C4 coils I've went through they have got that burnt taste within the first day or 2. One I remember got the burnt taste at 90 or 95 watts and the other at 105. I always prime them very well and before I start vaping I let them sit in my tank full for a couple minutes. I also start out low around 70 watts and slowly jump up 5 watts at a time until I get to where I want to vape at. They are meant for 215 watts. Ijoys customer service is garbage so I'm not even going to waste my time trying to get in touch with them over $8 coils but just wanted others feedback if anyone had the same issue. Thanks fellow vapors!!