I already had the air adjustment screw all the way backed off, and it was still a very tight draw. This is the Infinite KFL+ V2 by the way, which has the air adjustment set screw on the bottom, not the KFL+ which has the air adjusment screw on the side. The full air path goes from the side air hole, which was less than 1/16th (maybe 3/64ths or there abouts), across the air adjustment screw, into the central shaft, through the air hole on the side of the center pin, and up vertically through the center pin (which was right around 1/16th). I increased the diameter of the side airhole all the way through to the central shaft to about 5/64ths, and smoothed out the vertical air channel in the center pin to a smidge over 1/16th. So, at the tightest point, I increased the air diameter from around 3/64th to a little over 1/16th. This might not sound like much, but air flow is related to the square of the diameter, so I got a net increase in air flow of around 78%. (1/16)^2/(3/64)^2 is 1.777... So, even though it's a minor mod, it almost doubled the airflow.