Seriously??
A screw needs to be removed, that's the only way to fill it ?!?
Not true
Here is a top cap for the kayfun where you can top fill the kayfun.
Place your thumb over the airflow and fill your kayfun.
$2.72 Free Shipping Acrylic Kayfun Top Cap (Top Cap, PMMA, Blue) at m.FastTech.com
I wouldnt be caught dead using it because every single top filled Atty i have used has leaked on me.
I didn't say some, many, or most.
EVERY SINGLE TOP FILLED ATTY HAS LEAKED ON ME.