I found the connection on a schematic for my model on the Briggs website. It's on a 120VAC GFI outlet. They jumper neutral to ground at duplex outlet #2 and then that neutral line is shared with the other duplex 120V GFI outlet and the 240V 4-wire outlet (non-GFI). I was planning to use this to connect to the house...now thinking an interlockit installation.

I'm just going to un-bond it for my purposes. This is a big heavy troy-bilt job....it's for power outages only. It's not going tailgating with anyone. Although after looking a little it appears alot of those quiet inverter generators are floating neutral ironically.

I'll just re-bond the neutral if I ever use it in a different manner, or ever upgrade and give/sell this thing to someone else. Because I'm doing the work and research (including this thread), I don't suspect I'll forget about it. I'm going to have to buy some new torx drivers to get at this area, so