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. One last thing is that I have been through many C4 coils and have primed them and used them exactly the same way. It's just the last few have not lasted long at all and I have been using the same 3 juices for the longest time now. Thanks fellow vapors!!
Highlighted, underlined, and colored in bold. From your description you are "Priming" just about the way you should, however the C4 coil head is rated at 50 to 215 watts, being the minimum rating, aka minimum power needed is, 50 watts, start there when you go to start breaking the coil wicking in, much like a brand new car, you don't go 65mph or faster down the highway on a new car, you have to go max 50mph the first 1500 to 3000 miles so the piston rings and other components break in a seat properly, wicking is quite similar. Start at 50 and gradually go up 5 watts every 15 to 20 minutes, once at about 70 then you can bump it in 10 watt increments or stay at the 5 per step up. Alternative priming technique, take a piece of wire, hook it into the bottom pin of the coil head, have a jar or bottle of the juice you will be using and hang the coil head in the jar and juice for up to about 30 minutes before install, or in your case wrap it around the bottom threads with a hook at the other end, this allows the wicking to fully soak up all it can without flooding it as you can raise it up to hang and drain any flooding out back into the jar/container.
Other factors that might be going on, these are common across all coils, even rebuilt, hand made coils, coil killing or gunking factors
1) VG content, VG gets a double wammy, wicks slower so can lead to drying wicking quickly, also it can be used as a sweetener, depending what it was extracted from, Palm Seed VG especially falls prey here, that sweetening aspect crystalizes and doesn't burn off easily, which leads to #2
2) Sweeteners and very sweet liquids, these sweeteners crystalize badly, clogging wicking, and carbonizing on the wire and in the wicking touching the wire, you've probably seen it doing rebuilds yourself, that black gunk on the wire and black gunk bleeding out as brown in wicking, this is where 70% of it comes from
3) Dark and colored liquids, darker the liquid or more colorful the liquid, these colorings do "Not" vaporize, they collect and crystalize, see #2 above, clearer your liquid, less gunking
4) Creamy, deserty, savory, bakery, custardy, a lot of coffees, all tobacco flavors, a "Lot" of liquids in this category get a compounded whammy from #2 and #3 here, especially your tobaccos, coffees, custards, yogurts, cookies, cakes, anything buttery, creamy, vanilla or chocolate tones, tobaccos like WTA (whole tobacco alkaloids) and NET (naturally extracted tobacco alkaloids), you got impurities they will not vaporize off cleanly, creamy and custardy or yogurty, the list is long here.
5) Heat, more wattage and not enough evaporation (this one ties with #6 below), hotter that coil gets, more it breaks down the wicking even scorches it
6) Airflow, not enough air flow to match your heat in #5 to evaporate away heat in the vapor produced, coils get to hot and wicking gets burnt or breaks down faster than it should.
More categories you are in here the more things break down, already I see you have a triple whammy, heat in #5 and VG in #1 (double whammy for this one), and sounds like you are also hitting #6 so at least 15% of the compounding factors combined, if you have a liquid that is in #2, that is 85% coil killer territory right there.
