We have had several requests lately for a hookup diagram for Honda's GX390 series engine/generator. We recommend that an in-line propane electric fuel valve be used when the generator is going to be auto started by an inverter system such as Outback. We show a fuel solenoid valve being activated by Outback's 12vdc start/run signal that activates the GSCM-mini-i to start the generator. The hookup diagram was developed from Honda's GX390 electrical wiring diagram found in the owners manual. The GSCM-mini-i wires in parallel with the combination (start/run/stop) switch, and the 120VAC is connected to terminals 9 & 10 so that the GSCM knows when the generator starts, running and when it shuts down. If the generator is going to run once a week, you shouldn't have any problems with the small battery that comes with the generator. If the generator not going to run that often then you may want to connect a jumper between terminal 3 and terminal 4 so that when the battery gets low the GSCM-mini will start and run the generator to keep it charged. or you could use a trickle charger (battery tender) to keep the battery charged.
See PDF wiring diagram above.