Yes, I would much, much rather spend even $300 on a better pump if I can run it with my Honda EU2000i, 120 volt generator
than to spend the $300 on a cheap junkie 240 volt generator.
There must be something about the Grundfos pump motors that allow them to start on a much lower surge current than conventional motors.
Their 2 wire, 5gpm, 115v model#5SQ05-180-115v shows to have a FLA rating of 7.7 amps and an overload rating of 11 amps.
In their technical data, it says under starting current, "The motor starting current is equal to the highest value stated on the motor nameplate".
If that value is synonomous with what they're calling the overload rating, then I can understand how a Honda EU2000i could
easily start it.
Under features, it does say: Soft-Start: Both the SQ and SQE motors have a soft start because of
the integrated electronics. Soft start reduces the starting current and gives the pump a smooth and steady acceleration.
Perhaps the 'overload current' IS the actual start surge current; maybe it has something to do with them having permanent-magnet motors.