I have 4 of those Abu spinning reels my friend. The drags are very nice on those and rarely hang up.
The drag setting depends on a few things..
1. What size line are you using,
2. What lure are you using.
Really this comes from trial and error. For worm fishing I want mine set kind of tight because I don't want my line slipping much when I set the hook.Whenlive bait fishing ..and I know the hook is in there pretty good my drag is not real tight..
Rooster Tails also need a rather snug drag as the hooks can come out pretty easy ...so lure with smaller hooks diffently need a rather tight drag..
When your drag is working properly ..when fighting a fish your pole should be bent real good and your drag only coming on with extreme runs from the fish. If your drag is on when the fish is pulling and your rod is barely bent...you have to tighten up on the.drag. If your fish runs hard and your line breaks quickly ..not enough drag .

OR it's stuck. I always check my drag after my first cast to make sure it's not stuck up. With bail closed ..grab the line and you should be able to pull it out some. Again , trial and error. You can also adjust the drag sometimes when fighting a fish, If your rod is doubling over and the drag isn't woking..by all needs loosen that drag up some.

..real quick like.
OK I just went and tied a knot in front of 3 different reels and used my Rapala scales to see how hard to pull befor emy drag kicked on. My scale was about 6inches from the reel pulling straight outward.
Abu c 101 light reel 6 pound test...drag kicked in at 1 pounds exactly. Using minnows for crappie.
Abu c 103 20 pound power pro... kicked in at 3 pounds of pull. Rooster Tail was the lure.
Quantum baitcaster ..rubber worm kicked in at 5 pounds. using 20 pound Power Pro.
One reason I still use drag with my tough line...if the hook is in the soft part of a fishes mouth..although the line probably won't break..you can tear the fishes mouth in some places in his mouth and lose the fish.So the drag isn't just to keep the fish from over powering you..it also helps from tearing loose .Crappy have a very tender mouth thus the nickname .'Papermouth' Many of the big bass I caught this year..the hook was barely hooked under a small layer of skin.If my drag wasn't set properly ..I would hve lost that fish..When shiner fishing I had it set at 3 pounds although I was using 20 pound Power Pro.