When to replace my motors?

[PhantomFish]

So not too long ago I was flying one of my other quadcopters and in mid-flight one of the motors seized and the copter spiraled out of control while dropping like a stone. When I fly my Phantom, I'm usually hundreds of feet in the air and if something like that happened, it would most assuredly disintegrate upon impact with the ground.

Is there a recommended flight-time to replace the motors on the Phantom? If so, I suppose I can tally up all my flight-times from DJI GO and see if I'm due for a swap.

Have any of you ever replaced a motor on the Phantom before?

 

[With The Birds]

If your familiar with how they feel when spun and manipulated by hand you will know when. End and axial play along with bearing roughness indicate time for service or replacement.

 

[N017RW]

Yea. BLDC motors last as long as the bearings. And even that can be hundreds of hours and are usually replaceable or up graded.
I have over 600 hours on a CP heli with original motors/bearings/ESC.