i bought this and now i regret purchasing it. yes, it worked well until it got clogged up. vape gets you high when the weed has been vaped but once it has been clogged up or not put back together correctly, you will run in to problems. i have no idea what i was thinking in buying a butane vape.
Strange, I blow through mine and give it a quick brushing after each use (10 or 20 second job). After a couple of weeks when the draw does start noticeably getting restricted I disassemble it, pop out the screen, clean it, inspect and clean if needed the inside tube, then reassemble it (in the reverse order that I took it apart). Not more than a few minutes of my time.
Maybe you're talking about the outside of the cap ? That does get discoloured over time but that's just proof that you are paying your dyna dues.
Maybe it's an Omni and the air adjuster is plugged ? I've never seen an Omni so can't really help you out there.
I'm yet to use any vaporizer that doesn't require some kind of cleaning/maintenance routine but I find my Dynavap products one of the simplest ever in this regard.
To each there own I guess.......