I have a comp 12 that I'm using in P38. Can I use the ignition cutoff to shut down both engines? If so, how would I wire it?
Yes, you can but you need to change the connectors, the standard R/C connector cannot handle two ignitions.
You need to beef up all your ignition wiring to higher current connectors and good wire, from the battery through
the output of the Ignition Cutoff. Alternatively, you can add a second, stand-alone Ignition Cutoff to operate on
the same channel as the built in Cutoff and run it to the second engine.