I don't know if ball bearings are ok..but i'm little preventive for the engine..Thank you for your opinion and sorry that i have so much questions.
i would change them, for what ceramics cost its worth it, the motor is much smoother and pulls out of corners better, and also you will get alot more reliability out of it, since ive had sirio ceramic bearings in all my sirios the bearing maintenance has halved if not more