Having a problem with my motor. I had it on the car stand, no wheels just recalibrating my Radio and esc. When I gave it full throttle 3-4 times for approximately 2-3 seconds, the motor would lose 70% or so power with the trigger at full throttle, and the motor got very hot and even a slight bit of smoke.
Is the motor toast? What caused it to heat up so fast just bench testing it?

Running a brushless motor unloaded will make it heat up very quickly, never give a brushless motor full throttle on a car stand/bench/etc. for more than half a second. If you got any smoke at all, it got too hot. Sometimes the rotors will detonate doing that but in your case, it sounds like you got it hot enough to start to burn some of the sator. It will probably still run, it will probably not be as fast as it was.

It could be the gear-mesh was wrong (a bit tight). . .?

When it's unloaded it shouldn't get that hot as not much current is going through it. More current flows under load. The risk of doing so is that the rotor may disintegrate at high unloaded RPMs.

Turned out to be a problem inside of the motor, bad bearing

I can't tell you how many times we have guys send us an e-mail saying that a motor is overheating before it is even installed. We've seen this ourselves many times, if you run a motor without being connected to anything then the heat builds up really, really fast even though there is obviously much less current flowing through it. We have seen magnets come off of non-Kevlar wrapped rotors as well from too much RPM, it is never a good idea to run a motor full throttle without a load on it.

Smoke is definitely not a good sign. I'm not a motor expert but it sounds like there's some sort of resistance to the motor turning for her to smoke like that or something is caught in it like carpet fibres or something?

It was only 3-4 quick bursts. I didn't keep it full throttle for any good period of time. The problem was that something had happened while I had it on the track, and turned out to be a bad bearing and something a little loose inside the motor. So whatever happened was when I had load on it. I'll get it checked out and hopefully replaced.

Thanks for the replies!