Should Gen I Speed Sensor Rotor Spin Freely?

Warp 7

I took off my countershaft sprocket cover to inspect the sprocket and found that the speed sensor rotor spins freely on the driveshaft. My speedo and everything else is working fine. Is it normal for the rotor to be able to spin freely?

Thanks in advance...

~Warp 7~
Do you've lost the allen screw ?

Thanks for the replies. The allen screw is in place and tight on the countershaft. I will take it apart and fiddle with it now that I know it should be tight. Appreciate the advice from everyone.