[hkumudu]

When starting from ground , one or two motors start to speed up insanely (when increase from the neutral throttle position) and crash. On first flight after configuring wizard mostly work fine.but after that it goes crazy. Please explain whats going on.

[TheOtherCliff]

The quad is always a little bit unlevel.  Once the motors start, the FC tries to make the quad level but the motors are not spinning fast enough.  It tries harder and harder.  Same thing happens if it thinks it needs to do yaw.  It tries harder and harder.

If you take off slowly, the motors will get uneven like that and it will have a tendency to flip.

The best thing is to start from a level place (not the side of a hill), arm, start motors, take off immediately to about 1 meter height.  You should be able to do it within say 5 seconds.

Another thing is to not change settings without understanding them.  There are a couple settings that can make this worse.