Front forks adjustment

[Olyrider]

I believe, but I am not certain, that I can turn the adjustment screws (on top of the forks) all the way out, and they won't just fall out of the forks? The purpose being that I would know the softest setting possible, and then I can add some stiffness back in.

I couldn't detect a click when turning the screw. Is there one, or do I just pay attention to the number of turns? Is one 360 degree turn enough to make a noticeable difference, or is that too small a change to have any real effect?

Thanks!