since the gear`s bushings are new and tight ,
you have to make a breaking (use it a little)so it loosens.

the other thing , since it is stiff to turn ,
you push longer on the controller to make it mouve 1 second, so , if you have pushed the stick 3 seconds ,it will try to go for 3 sec.
this is wy it continues after the comand.
do you understand ?