You can move the wick but it doesn't look easy to do. You can also put a small hole in the wick but it seems kinda risky; too big a hole and you just trashed your atty.
juice is a huge factor I think too; I use 100% vg and it takes a lot longer to wick. Great vapour but so long to wick sometimes. Charcoal taste isn't awesome.
PV/VG mix would be better. I also find, especially with my LR atty, it takes a few drags to really get going. First three puffs or so are weaker on vapour then it gets better from there. My 100% PG stuff is really puny on vapour but my 100% VG is pretty godly on vapour even in the tank. Still prefer to drip with my 510 but just can't beat the convenience of the tank.