how many battery packs do you think you've put through it?
I have a meter on my heli that jumps down to red just before a motor is failing. That is a great safegard for me, because I have had 2 motors now that blinked red on my meter, so I brought it in for a low close hover, and both within about 5 min bit the dust and sent the heli piroing. No damage done though so close to the ground. Just ease back on the throttle and set'er down easy.
I agree with trug, a spare is always a nice thing to have. you may want to break them in first too. I have a guide that is in the forum just above this one as a sticky.
ORIGINAL: LostByChoice
I was having the same problem, the guy at HeliHobby told me that main motors will last about a year or so...
hehe yeah, they may very well last a year if you only put 1.5 or 2 flights on it per week =) It's better to go off packs or flight hours instead of months days or years just because how much people fly their heli has a real big range on it.