The tail motor only spins one way. Its either off or on. Off the heli turns one way motor running or on it turns the other way.
If you tell it to turn it should turn that way turning off or turning on the tail motor. If it won't there is a gyro test in the manual that I think tells you to disconnect the main motors and turn the heli by hand to get the tail motor to start up by the gyro. If the rear motor is running and nothing will get it off it may be bad. When the tail motor goes it will stop running and not run or run all the time.Don't think you need the gyro test. Rear motor or gyro adjustment if you turned the screws on it. Ron