Micro-t help!

[AP Alex]

I have a BB motor installed in my micro-t with a lipo battery. After running for 10 minutes on Monday, the motor will not turnover when trottle trigger is pulled unless I give it a little twist with my fingers. As long as the shaft is turning, the trottle will speed up and slow down the motor, but when the shaft stops, I must restart it by hand. Is this a bad motor or esc? Help!!