i have an older gs1930. serial number 6996 when using it, it becomes jerky in all mode. forward, backward, steering and up and down. i replaced the joystick and no difference. do you think it is the motor controller? how would i tell? thanks tom
Put a gauge on it and watch your hydraulic pressure. Easy way is to put a jack under it and jack up the drive wheels so you can use the control box and actually watch the gauge. Id check that first.