Nitrofever3D

This were tonight they were about 10 feet up still trying to get the gyro right.It always pulls hard to the left when taking off and then once in the air it rocks back and forward then once the batterie starts to lose a lil of power after fully charged it goes away and starts to pull right i dont get it.The other night it was fine but now it just does that and i have to control the tail at all times and i think the Delay Adjustment Pot(gyro gain) + clockwise counter clock - is wrong on the book correct me if im wrong????Need input!!!