My dark magic has always been responsive. I’ve recently siliconed the reccess with flowable silicone, sanded down the starburst, and I put in a cleaned konkave bearing, and its still completely responsive. Any tips ??? practicing whips is completely impossable 
well doing all that to it was unnessassary sry miss spell shouldve just got some thickshims(the red ones) space the gap a lot also possibly to thick of string.
YYJ ships their Dark Magic’s responsive out of the box. KonKaves can also get pretty responsive also. Purchase some thin lube. One drop of that stuff, and alot of play after application of the lube should help.
A side question, when you flick the bearing, does it spin well?
It only spins for about two seconds when i flick it :-\
edit: my bad i meant to say 4 seconds.
Then it’s a problem with your bearing. Lube it, see if that helps, if it doesn’t, you may want to deshield it. It THAT doesn’t work, buy a new bearing.
Hmm… did you do anything else to your DM?
Check your silicone. Make sure none of that is in the bearing seat.
Since your KK doesn’t spin long, try using the original YYJ bearing, cleaned.