I'd say it depends on what power and info the circuit needs... you could probably work something out with the ignition switch ON & OFF positions. Just cutting the electrical power will not kill the engine with the EDIC system. I think we need to know more about the timer
Jon, what do you mean exactly ?
IMO a healthy B is just as good as a 3B in stock form.
The advantage of the 3B is its turboability for a big power... Still I think a B could be safely turboed if pressure is kept reasonably low... in the low-end grunt style for which these tractor engines were designed...
I'm going to experiment on both in the future anyway