You'll really want to do the straw mod and use rolled pyramid tea bags as the filler once you get your e juice. I swear it made my device 100 percent better. I have to reiterate that the pre-filled carts that came with the Njoy are horrible, they're way to dry the poly fill inhibits the vaporization. Try these methods to just one of your carts and you'll be amazed. For the straw mod get a very narrow straw I used one from a juice box.
on a scale of 1 to 10, ten being the best vaping experience on the rn4081
I started with the prefilled carts, rated 2
Then I tried the Lipton Pyramid Tea Bag (PTB) mod, (remove old poly fill and glue from the inner cart, wash inner cart, roll tea bags loosely, put roll into inner cart cut PTB, you want it to almost reach the top of the inner cart use two rolls if you need to but make sure they are loose if it's too tight they won't absorb liquid correctly. Rated this mod a 5
Next I did the straw mod, remove roll(s) of PTB, take a thin straw cut one end at an angle, put angled end in inner cartridge, again cut straw so that it almost reaches the top of the inner cartridge but not all the way to the top, replace the rolled Lipton pyramid tea bags, so what you have is a straw inside the inner cart with the rolled tea bag squished against it taking up most of the room in the inner cart. Straw allows air to get to the bottom of the inner cart which forces liquid up to the atomizer which helps to produce insane vapor in an rn4081 model. Rated this Mod an 8.
Now there is one more mod to do purchase the dbl cartridges, they are longer than the typical RN4081 cartridge, and the inner cartridge is about twice as long as the regular cartridge, this will hold dbl the liquid. (I can't find these in Canada
but easily will Rate it a 10 if I can get them.
P.s. Two more tips when you get your eliquid, after you top up your cartridges put a drop of liquid on the bridge of the atomizer to get it wet, (but don't put more than one or two drops on the atty cause you'll flood your battery) when storing always make sure the LED end is pointed to the sky and not to the ground cause liquid will run into the battery and flood it.