I have a Joye 510 and barely get any vapor. I've tried drawing fast and slow (mainly I do slow drags) but still get minimal vapor. From all the videos I've seen on youtube about the 510 they all have excellent vapor production. I can't figure out what I'm doing wrong. I've been topping off the cart regularly so it's not lack of juice. (shrugs)
Low vapor with any e-cig could be several things... bad charger, dud battery or flooded atomizer (have you tried blowing it out from the battery end of the atty?).
Also could be that you don't have a great atty (is it a Joye, or one of the Clones with a washer ring inside of it?). Clones can vape poorly.
Also, a 510 really requires a drop of liquid on the atomizer bridge (on the metal mesh inside the atty) each time you refill your cartridge (and when you start to use a new one, 3 or 4 drops on it helps). You must keep it wet to have great vapor. It can take someone new a little while to learn the 510 but once you get it, it is a great unit.
Lots of 510 info here:
Joye 510 - E-Cigarette Forum
I actually got 30 ml of liquid in my starter kit but all my carts are pre filled
One of the biggest mistakes with a new e-cig is thinking that prefilled carts are going to last all day. You need to top them off after a little while (off or burned taste or when vapor starts to decrease).
Most likely, you have a cartridge that you can remove place drops on the white polyfill in the mouthpiece? If so, get your liquid out and add some drops to the cartridge and a drop on the woven mesh of the atty bridge and I'll bet you make great vapor. Don't be afraid to use the liquid!!