Enjoy that fresh coil Robin!
What would tighten up the air flow on a kayfun? My sister builds the same coil as I do, 7 wraps of 30g for 1.8 ohm, rayon wick. I'm thinking possible gunk buildup inside? Maybe a boil? Yes, she checked her AFC, wide open.
Probably some gunk in the center post , pipe cleaners are handy for that sort of thing .
Yup, I'd agree with that, boil, or a hot soapy soak and either pipe cleaners or a dental brush through both the center post and air intake holes.

