Clutch arm motor lifting

I am using the Vex IQ clutch robot model. Whenever the automatic program tells it to raise its arm, it only raises partially and stops. It sometimes goes all the way up but rarely. On the programming, I set it moveMotor (armMotor, 315, degrees, 50); What is wrong? Please help.

P.S. sorry if I miss anything and for the bad robot language. This is my first few months in robotics.