you know...ive never opened my MMM case...nor the motor
but...you should never spin the fan over with a compressor, (this only apply the brushless fans i think) cause it causes back EMF that can fry the fan.
E-revo 3.3 conversion, 249kv outrunner, 6s, MMM
the porthole from the noob world an here has been opened!! that's how i got in.