This is a new Viper with a new transmitter. I noticed that the new transmitter was fine except for the rudder control - it was very sensitive and made the model hard to fly smoothly.
This is a video to show how to adjust the sensitivity to suit yourself. This detail is in the manual but I though it would be useful to show as it took me some trial and error to figure it out, even after reading the manual.
To change the sensitivity -
1) Press in the right stick and hold for one second to access the setttings menu.
2) Click in the left stick briefly to select the control you want to alter (look for the flashing blocks on the display to show which control is selected)
3) Use the rudder trim control to chenge the sensitivity.
4) To adjust the 'expert' mode setting, click in the right control again whilst in settings mode
Note: The larger the number - the more sensitive the control.
Thanks for watching - Happy Flying!