That means it's the Kink East coaster, an aftermarket hub but it comes stock on the bike you have. I have no idea if they would have included the slack adjustment washers in a bag that came with the bike or not.
It engages by pedaling. When you pedal, the hub's engaged and driven your cranks as you pedal forward. It disengages by back pedaling a certain amount determined by how much slack you have (Which is determined by how many adjustment washers you have, the more washers = the less slack, I think so anyway. Freecoaster knowledge isn't my best subject) and when it disengages, basically what happens is the driver detaches itself from a piece inside the hub known as the clutch.
The reason for this is so when you do a 180 or any trick you land going backwards, is so the driver does NOT engage, and thus won't throw you off the bike like a cassette would. Instead, the wheel will spin freely backwards or will stay disengaged until you take a crank which will then re-engage the hub but also with a short "delay" before it pedals again which is the delay you're feeling.
Did you know it had a freecoaster when you bought it? Seems like you don't want a freecoaster or know how to properly use it anyway, not trying to be a dick when I say that though