wilmpie

hi everybody I have a kymco mxu 250 automatic from 2006 250 cc that keeps going forwards or backwards when i shift backwards or forwards an then shift to neutral . if i shutdown the motor and push the quad and restart then its in neutral and don't go forwards or backwards, i already checkt if my motor is running good stationairy . what can it be or what can i do to fix this? thanx in advance p.s. Sorry for my bad english it's not my first language.