[morzh]

If it is the transformer type asynch motor, it relies on not being stiff.
if you give it a start with your fingers while unpowered, it should freely rotate for a few seconds.

If it gums up like that you have to take it apart and not just lubricate it but clean it first.
Then some of those motors have a plain bearing whith a ball, like so
http://www.pkkazan.ru/support/vibor/
where the axle goes.
If this ball is slightly off-center this will impede rotation. The ball might have a compression seal made of felt or similar material soaked in oil. This ensures the ball itself rotates freely and so sels-centers when the motor is assembled.

So the sleeve (both sleevese, butt and front) has to be cleaned, and then the back ball fitting (gasket) soaked with some penetrating liquid oil (not really lithium grease). Then everything lubed and assembled back.

The rotor should freely rotate without any impediment.

Again, if we are talking of the motors I have in mind.