The coil will look pretty burnt and black really quickly, especially with darker juices. It's not burnt, it's just the
juice gunked up on them. Same thing happens in a carto, you just don't see it.
Don't be shy about tilting Fluxos, even upside down. They won't leak. You might try trimming the wicks a little bit. They taste better and wick at least as good if you trim the bottom 1/4 off of them. If you normally vape with your PV in a vertical position, you need to make sure you tip it horizontal frequently. If you vape more horizontally, you'll really only need to do this when the
juice level gets real low.
Also, don't over drive them. That will make your
juice taste burnt. The coils are pretty tough and instead of just popping, they'll taste burnt if your voltage is set too high. I use the 2.6-2.8ohm on my Vtube and usually have it set to 4.1-4.3 volts.
Here are some tips and tweaks you can do with your Fluxos. I don't do all of them all the time but, now and then, they help a particular carto.
Clean them with hot water before you use them the first time. Take them apart, rinse them and then pass a lighter flame over the wicks. Do the same thing to the cup and coil. Don't melt the plastic insulation on the wires or the shrink tubing under the cup. You won't burn the wick. Do it until there's no more steam of vapor coming off the wicks. That will get rid of any residue left by the factory. Then put it back together, keeping the following in mind:
Don't try to remove the plug when the fluxo is assembled. Take it off only when you have removed the tube. It's a lot easier to deal with when the tube isn't in the way. Put it back on before you put the tube back together. The one-piece plug is a little different than other clearos. It's easy to get it tilted or out of line if you try to put it back in with the tube already on the base. Get it good and lined up, lube it with a little juice and slide the tube over it. Don't jam be plug down too tightly on the cup. When you put the drip tip on, it will push it down evenly as far as it should go. It's easy to put it too tight on the cup or to inadvertently twist or tilt it and restrict the wicks if you do it with the tube on.
When you have the plug off the coil cup, check to make sure the coil isn't sitting real high in the cup. If it is, just push it down with some tool. Be gentle. The only place I've seen these burn is on the edge little lip on the underside of the plug. It usually is very minor and almost never noticeable. You can trim that lip down a little if you want, but by the time you notice it, it is probably no longer contacting the coil and has stopped on its own.
Also, while you have the plug off, hold the coil down and pull the wicks up a little to where they exit the cup at the top of the slots. This can help wicking.