I saw a guy on rcuniverse, he had a similar problem with a feigo or neu-motor. The rotor broke in the can (sintered). They mentioned something about applying epoxy, I just dont know if that will effect the balance. I dont know what the thread is, but go to their electric forums and peek around. Wont be hard to find.
R40-Pondering a new Red Dot
Hara Pro4-GTB/3.5/Max Amps-yea.
Pondering moving on to Xray-have to go with a winner. If you cant beat em, join em!
I gear to run and win, not to THERMAL!