Fried Motor - Thoughts?

So I’ve failed… Pretty Bad. Here’s the story… I lost a screw on my motor mount so I went and bought some new short M4 bolts/screws. I installed them with threadlock. The motor was still able to spin if I turned it by hand so I turned it on and spun it up just to check it was all good and disaster struck. It literally caught fire, there was a flame coming out of it. There was some smoke too. I immediately stopped it. After I spent some time just looking at it with my phone flash light through the small gap between where the motor gets screwed on and where the motor spins and none of the screws were touching any coils. The only other thing which it could have been is some threadlock had dripped down onto the coil and either shorted it or something… I’m not too sure. It could have been some vapour, I’m not really sure. I mean I know it would only take a slight brush of the coil against the screw to short out but I’m pretty sure it doesn’t touch at all. Video of it turning freely - nothing is catching and it feels like it should:

Video of the motor trying to spin with the controller:

Just wondering if anybody has any insights into this or thoughts on it… I’m going to have to buy a new motor but just interested…

I’ve seen similar behavior on a quadcopter when I have a loose wire between the ESC and the motor from crashes. Since you saw some fire coming out of there can be pretty sure it’s actually shorted inside the motor, but it is strange there’s not any tension on it when you are turning it by hand but I guess if it’s just a short in one coil not across a pair of them you might not get as much resistance as when you touch the motor phase wires together and try to turn it.

Is the video of you using it with the controller before or after it caught fire? Anytime you test your setup with controller never full throttle it. If things are supposed to be moving and they don’t and you’re throwing loads of current at it, something will catch fire or burn. First tests should always consist of very short, very slight, movements of throttle until you verify things are reacting appropriately.

The video is after. I didnt get any before. I did do it slowly to test, it was okay so spun it up to full speed… Thats when It happened.