There are no "kill switches" for nitro engines. Only way to kill 'em is to close the throttle, are you sure your carb throttle settings are correct? Forget the needles for now and concentrate on setting up the throttle arm.

Here is some good reading to properly setup the throttle arm.
[link]http://www.ronlund.com/rcheli/ARCHIVE_THROTTLE.html[/link]

Rafael