When I arm the drone the motors start rotating at some throttle percentage may be (7%) and the drone will automatically disarm after 14sec and again the process repeats after I arm the drone.

After some research, I found that this can be controlled by the parameters like `MOT_SPIN_ARMED` and `THR_MIN` but these are not available in the standard parameters list like in the video I saw.

I tried manually resetting the values like setting `MOT_SPIN_ARMED` to 0 and `THR_MIN` to 30 then the motors not started spinning when armed but when the throttle is given all motors are not in sync one motor starts at a different throttle level. I also performed all-ESC calibration and everything goes fine. But the motor yet picks up at a different speed. But when I reset the parameters the motors are all in sync as expected. 

I'm not sure why I can't find the `MOT_SPIN_ARMED` in standard params. I'm really troubling with this issue any help is highly appreciated.

Firmware: Copter stable v3.2.1
Arducopter version: 2.8