A little loose is fine, you want them to be able to move around a little. Be sure you have a good nylock nut, or blue threadlocker on the threads so that the bolt doesnt back out.

Todd, if you’re talking about that pinch bolt on the cassette, the only way that would cause a bind is if the bearings are miss-aligned.  When the kart gets back on track, the bearings will find their alignment.

It’s very difficult to judge how tight the cassettes are around the bearings unless they are in your hand.  When they are in your hand they should NOT be loose, but able to move freely with a little resistance.  You’ll get the idea when you feel them in your hand.

Hope that helps….