IMO it's fine to test a motor with no load on it, you just have to use common sense. Of course pinning the throttle and holding it wide open for minutes will cause problems, but doing short tests at low to mid range throttle for a few seconds at a time isn't going to harm anything.

+1

running a motor with no load won't turn it into a grenade:lol:

Dont panic
 

Yea I do not see any reason to panic about this. Testing a motor of any kind with no load is a fairly common practice in industrial areas. I am sure that most motors are under rated as to their true top RPMs, so you would never want to wind any motor out without being attached to something. The outcome could be catostrophic to the motor and even dangerous. The sound you were hearing was directly related to the fact that you were running it in your hand. Most likely the motor is fine.

+1
Running a motor without load at full throttle won't do any damages...
Thoses NMB bearings are rated for up to 100 000 RPM, so there is no way you damaged it on a no load test.
I personnaly tested a CC 2200Kv motor and other CC motors at full throttle and no load during minutes, and there was absolutely no problems, the motor seems the get warm quickly (40°C) , but it's because it's in your hand at 34°C and it can't cool itself with air flows like it does normally in your vehicle...
So stop panicking when you see someone testing its motor with no load...
More over it drains ~2-3 amp during no load test, so what's the risk guys ??

+1

It's fine to run for a few seconds with no load. Just never run an extended period with no load -- the motor will overheat quickly with no load.

The 2200Kv motor will be quite loud with no load. Remember, the RPM is EXTREMELY high with no load -- it will make quite a racket. :)

-Patrick

Absolutely, but what kind of noise?
AFAIK would be a loud whine, right?
Not grgrgrgrgrgrgrgrgr

Make a movie with good sound and upload it on youtube. Then post the link here.