Is a supercharger snout supposed to be stiff to turn?

Hey guys i just bought a supercaharger off a guy. It came off a 1997 GTP. So its a Gen 3 eaton M90. Now i got this taken apart, cleaned the rotors with a dry clean rag, and got all the carbon out. Now when i try turning the pulley on the snout, WITHOUT IT HOOKED UP TO THE GEARS FOR THE ROTORS, it seems stiff. It doesn't seem to want to bind in any certain spots, its jsut stiff to turn. I don't have to strain to turn it, but I'm just wondering if i got sold a fryed blower snout. Is this thing supposed to spin like er smooth or something? Thanks for the help!