That is my point why must the engine be shut down if the receiver looses signal. Most lower end radios do not have this ability. That is why they go to full brake in the event of signal loss to stop the vehicle. The only time that would not work is if the throttle servo went out. The OP made a great choice in buying a futaba radio they are the best and generally don't have any issues with signal loss unless they go out of range. The OP stated that the failsafe is setup on his
3PV and the brakes do go into full brake when the radio is turned off. The only other senario is that the battery voltage dropped too low and the receiver shut off, in this case the kill switch would still not work because the receiver is dead and there is no power to have it control the kill switch.
Your reciever is not the issue. it is your transmitter that is not able to set a user controlled program for the 3rd or 4th channel in the failsafe menu. The 4pv and up are all capable of doing this. I have owned the
3pv, currently own the 4pv and 4px. You physically can not get a kill switch to perform the function you are asking it to do with the radio that you have.
Scruffy what transmitter are you using?