Greetings,
maybe I was bored. Maybe to much doom and gloom on all the bans of new gear and the shipping of it. I started to think - why not have some fun with some of the stuff I already have?
Another negative is that while it is top fill, there is no juice flow control so the atomizer get flooded each time the tank is refilled. While I could (and have) used it in a pinch, I can get 1-2 tank fills on a single 3000mah battery.
Like others have already stated, that is a Kayfun V4. It's an awesome tank, way too many parts, but still a great vape. After the juice tax dropped here in Nova Scotia ($0.50 per ml) I dug mine out of storage and retired all the cloud gear.
If the airflow is too restrictive then there is a air tube with a large bore, It's called the 4S-Kit and opens up the KFv4 considerably. They are hard to find these days so you could just take out the Air Regulation Screw (#13) from your stock Center post (#14).
If you don't have the KFv4 diagram then it is a must have to familiarize yourself with all the moving parts.
The Kayfun V4 has a spring (#12) to maintain conductivity when the juice flow control (#5) is fully open, this can be the weak link for ohm fluctuations and improper readings. The tank should always be run with the JFC wide open, that way the spring is fully compressed and gives the best conductivity.
If the base (#3) and JFC ring (#5) are hard to independently turn, then large slot screw (#9) might be too tight, it should only be snug and not cranked down.
Before filling by removing the top nut (#38) always spin the JCF ring counter clockwise to close it off completely then remove the nut.
The JFC ring is attached to the Evaporation Chamber (#28) and I make sure those are very tight, that way you can use the whole tank to spin the JFC instead of trying to get your fingers on the ring. Make sure the Counter Nut (#33) is tight as well to keep the top tank section from coming loose.
Looks overwhelming but it's actually quite simple.
