Yeah I can get a nice draw just little vapor. Its dual coil and has 2 holes opposite each other. Do u add more juice as its used or do u wait till its almost gone to fill?
First of all, the "punched" (juice holes) cartomizer needs to be properly primed, or pre-filled, before it goes into the cartotank. I'm assuming that you know how to do this...if not, we can advise how to do this. This is the most important step in a cartotank setup.
Once the cartomizer is primed, it can be put in the tank and the tank filled with juice. There should be no need to add additional juice to the cartomizer after this because each time you take a puff from the cartotank, the vacumm created in the carto causes juice from the tank to enter through the punched holes in the carto.
When the tank itself gets low on juice, you will need to add more. The choice to add additional juice to the cartomizer at this time is up to you - some people do and others do not.
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I haven't used dual coils in over a year, as I prefer single coil cartomizers in my tanks. You may find that you have to use higher voltage with the dual coil cartos to get the vapor that you desire. Raise your voltage up in increments up to 5 volts and see if you get more vapor without getting a burnt taste to your juice.
Your Vamo reads the dual coils as 1.5 ohm, but in reality there are two 3.0 ohm heating coils in the carto. You probably need higher voltage to get them both to heat up enough to make adequate vapor. This is just one of the reasons that I don't care for dual coils, because they require more voltage from the battery and drain it faster than a single coil cartomizer will.