I think tuning the
kayfun is a lot like tuning the fuel injection, or more like the carburetor on a racecar, it's always comes down to either too rich or too lean, with the sweet spot being right there in the middle. the challenge is to first be able to identify weather it is too rich or too lean, and then secondly to figure out what to do to move it towards the other direction with the variables you have in the build
if you are too lean then your not getting enough "fuel" to match the coil and airflow, to compensate after the build you can either draw more, do primer puffs or block the intake and pull a bit to add "fuel" periodically. if you are tuned too rich to match the coil and airflow then you will get gurgling and eventually flooding, to compensate after the build you can pre press the fire button a few sec before drawing and hold it a few sec past the draw, if too rich it can eventually flood and then you'll need to clear the passage by blowing the excess out of course. ideally you want to get the build to be as close to "in the middle" as possible with just normal draws.
the main variables in tuning a build stem down to altering the coil and the wicking material and actual placement of each. personally, I find with true microcoils that for me, just a little cotton in the center of the coil alone is not enough, it is if the coil is a bit larger, like on just a smallish coil but on a tiny micro not enough, I find that I need at least some cotton added on the top or side. I've tried a lot of different setups. cotton on both sides can give me a really great feed but results in a very flavorful but cool and muted vape and poor vapor production, I think too much of the vape(air/fuel mixture) winds up being filtered through the cotton. I get better results with cotton added on just one side, leaving the other side open for airflow
recently I've been playing with no cotton in the center of the microcoil at all and just cotton on one side and on top, leaving the bottom and one side of the coil open directly to the airstream as it flows across from intake to exhaust. my current build is the same 3.8 ohm ribbon micro I posted a few days ago with no cotton in the center, I have just one piece of cotton that drapes half way over the top and packed to one side of the coil. so far it has been really really good. nice sweet vapes at 6V, not huge vapor production like a genny but a nice balanced hit each time, the right hit for a stealth vape I guess. I like to be able to pull it out in a store like staples, take a nice draw yet not blow clouds afterwards. this is the kind of vape you can short draw and hold in long enough to exhale almost no vapor. I can vape without anyone really noticing, no one gets offended when they don't even notice your
vaping 
next build I'll probably try exactly the same but maybe bring it down to 3.4 ohms or so. I made a quick vid to show the vape. I use a tiny tube I just picked up to blow air into the intake to show the draw here. this is a little less than 10 watts, I'm blowing into it around as hard as I would normally draw. next build I'd like to kick it up to a little over 11 watts but everything else the same. first time doing a vid on photobucket hope it works, click the pic I think
