I have done around 150 flights, and started to think about the longlivity of the Spark. Has anyone worn out their motors yet, and had to do some replacements?
I'm no expert, but I know they are brushless motors, and the only thing to "wear out" are the bearings. I have a feeling you'll either crash or have some other electronic or mechanical failure before the motors wear out. My Mavic Pro Platinum has the most flights of all my drones - it has 151 flights, over 21 hours of total air time, and over 126 total miles of flight on it. I'm sure that is really low. Maybe some others can chime in with their big numbers.
I'm only at 15 hours on the spark but I've been reading Spark forums for a while and it's not exactly a topic of conversation. I don't think I've ever seen anybody posting about it happening.
I got lucky when I crashed mine, the prop wedged between the house and the gutter and then it fell about 3 feet to the concrete. Anyways, long story short it buggered the motor. Quick replacement ordered from Amazon and I was back in the air in 5 days.
Lessons learned for sure after the crash. These things are pretty tough but, like others have mentioned you'll most likely kill a motor on a crash, rather than it wearing out.