The only configuration you need to perform to have tap/double tap operate the RUN/KILL function is to setup the Controls menu, selecting 5 button option.
Pressing START once will fire the engine. A quick double-tap will KILL the motor. If it doesn't, you either have a button ground issue, or your mUnit is wonky.
If you want to verify the mUnit, create a small jumper for the START input. mUnit ON, ground the START wire. Motor should fire. Break the ground and double-tap the input. Does the motor die? If so, check your button wiring.