The burnt taste is because there's not enough
eliquid in the atty.
Popular solution, prod the wick down a little in the actual piercing straw. If you shine a light down there you can see there's a bundle of fibre in the middle straw. Podge it down a little with something carefully. If that still doesn't work, use a small needle and poke a small hole in the wick carefully. Be really careful doing this. If you push it too far down you'll have to take the whole plate out to reposition it or if you make a hole in it that's too big it'll be damaged beyond repair.
What I did with my tanks on the first fill is fill the carts up then leave it upright overnight. It really helps to suck through the mouthpiece as the wick works on vaccum pressure. Suck through the mouthpiece a few times reasonably hard and leave it upright.
If you use thicker liquids it'll take longer to wick so keep that in mind. I used very very thick 100% vg and it still wicked, just slower. I could get 8 - 12 puffs then had to leave it for 5 minutes. If it can work with liquid as thick as that you should be ok with anything but it's adviseable to use a higher pg content than vg if possible as it's a thiner, easier to wick liquid.
If you leave a tank upright too long it can leak. My partner tells me his leaks often if he has it upright for a while but I had to always leave mine upright because it was a much thicker liquid. A bit of getting used to.
One other thing that's a possibility is, did you really blow it out before your first use? If there's any "primer" in there it'll be a bad time for you until it's all gone. Blow it out, fill it up, suck through the mouthpiece, leave it for a couple of hours then vape it back in.
If all else fails ask your vendor for a replacement if it's under warranty. If it's not working, it's not working.
Nice choice with the ego! I reccommend, you get an 510 to 808 adapter and put some 808 cartos on there or just drop a few $ on 510 cartomisers. I say 808 adapter because you can still use your 808 batteries if you want to or in an emergency and cartos are really nice if you fancy a change. It's a small amount for an adapter and some cartos just to have on you. I still have ego tank atties but they've been totally replaced by 808 cartos for me because they have a really nice warmth and so so much more flavour than tanks. I'm not saying what you have is wrong and wont work, I just prefer them.
Good luck and let us know how you get on!