Davies... It looks like you have three leads (two browns and a green/yellow) from the generator to your "remote outlet" connector. What I can't see is whether the two browns are to different terminations or the same one at the outlet. My guess is you measure 110 from each brown to green/yellow.
The motor leads are in pairs (parallel) to handle the output current requirement. There are two each to terminals 1,2,6, and 7 within the generator terminal box. The brown external leads are connected to T1 and T7; the green/yellow connection runs from the generator to T6, which is then connected to T2, and from T2 out to the "remote outlet".
To double the output voltage, the coils have to cut twice as many flux lines in the same time period. That happens by either doubling the frequency (i.e. spin faster), doubling the available coils passing through the flux (i.e. more turns per coil OR more coils), or radically change the machine geometry (affect the flux distribution factor).
Converting energy to motion for more than half a century