Try to line up the atty bridge /\ and the juice cup
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Try to keep the stuffing damp so the atty doesn't get overly hot
And buy the cheap precut blue foam stuffing for 510 carts at strictlyejuice.com - it wicks well and won't give as much burnt stuffing taste if dry. I love blue foam. Stick the tapered end into the cart. You can fill the cart 1/2 way with juice, stick the blue foam in, push it into the juice to get it wet, reposition at the top edge of the juice cup, then top off with 2-3 drops - whatever it needs. After that you can just top off for a while whenever the vapor seems a bit drier or light. When topping off doesn't help, you do another full fill. An smooth small unbent leg of a paper clip is good for pushing and positioning the stuffing.
I love blue foam - holds its shape, even consistency, easy to rinse or and pat dry.
And I recommend you also try cartomizers. Get a pack of standard resistance (not LR) Boge 510 soft-cap cartos at LiteCigUSA.net or elsewhere. The mouth-end cap pops out - stick a paper clip end in the mouth hole just far enough to pop it out. I hold some tissue on the threaded end, hold at an angle, and try to add about 1ml into the stuffing (20-28 drops with most bottles). Clean up the threaded end well! Puff into the threaded end with the open end down into a tissue to clear the air channel. Clean up and jucie pooled above the stuffing. After the first fill let it sit for a while so the juice will soak into all of the stuffing - I lay mine on its side, and change which side a few times.
You can vape a LOT longer on a carto before it needs juice. If the juice gets light or a bit dry, try tipping the ecig carto down for 5 secs and if that does not revive the vapor, add some juice (5-10 drops or whatever it needs). take the carto off the battery when you add juice and again clean the threads, puff to clear the air channel etc. If you keep it damp it should be vapable right after adding more juice. And if you keep it damp a carto should last for 4-7 days and I have even gottena couple of weeks out of those Boges.
NOTE - If you have auto batteries you need to be extremely careful not to get juice drips out of a carto. Juice drips can kill your drag sensor and your battery. Manual 510s are sealed on the threaded end so you just have to keep them clean (both sides of the connection, especially before screwing your battery into a charger or PCC (a film of dried juice can decrease performance or even prevent electrical connection.