Brand new Yamaha EF6300iSDE instant overload (with video)

I doubt ya Bill because the Honda's between 2KW and up to the EU7000i seamlessly work from the factory with any neutral bond issue.
Certainly easy to test for though!

How does the genset power heaters or large loads external to the 4024? measure AC under load with a true rms Voltmeter

make sure the 4024 has its AC parameters as wide as possible.

It sure looks like a bad genset from this far away. Nice troubleshooting!  Good Luck and at least the dealer is close by. Smart of you!

Perhaps #1 isn't clear to some - it's the generator that is going into overload and switching itself off.    Try some type of soft-start added to the generator's load (ie, output).

Could be that that generator has a quicker reacting (or faulty) overload detection circuit.

will the dealer lend you another brand new one , at least that will eliminate the new gen as having a fault 

ron_jeremy said:

Any idea why this is happening?

There are a few possibilities, but you'd need test equipment to figure them out.

1) Startup surge.  You can measure this with a current probe and a scope.  If this is the problem a precharge resistor might help.

2) GFI fault.  You can also measure this with a current probe; you put _both_ wires through the probe (so the differential currents cancel) and look for common mode current.  If it's too high it will trip the GFI, and that might be reported as a fault.

3) Power factor.  You can measure this with a scope; you have to measure current with a current probe and voltage with a regular (voltage probe.  The current waveform should ideally be proportional to the voltage waveform but it rarely is.  If it is "peaky" it means that you are peak charging inside a rectifier circuit somewhere, and that may exceed the generator's maximum output capacity.  If it significantly "leads" or "lags" the voltage waveform then the generator may not be able to support those sorts of inductive or capacitive loads.  If this is the problem, capacitors (to compensate for inductive loads) can help.

4) EMI.  It is rare but occasionally a load is so noisy that it causes problems for an inverter (or an inverter based generator.)  Again you would see this with a scope.  If there is a lot of high frequency noise on the voltage or current waveforms that can interfere with the inverter inside the generator.  If this is the case an EMI filter can help.

What you are calling " 60 second "handshake" (AC In Good 2) period ' is the inverter detecting AC input voltage and the time is the inverter slowly slewing it freq/phase alignment to match generator.  The actual time it takes depends on the initial phase/freq difference between AC gen and inverter phase/freq.  More initial freq difference will take longer for inverter to sync to generator.

After inverter syncs to generator, the mechanical 'click' you hear is the transfer relay closing and paralleling the generator to inverter.

This is the point where a common mistake is not having pre-set max inverter AC input current limit and/or maximum battery charging limit on inverter so the inverter AC input current draw does not exceed the capability of generator as soon as transfer relay closes.  Since the lower power generator works, I assume this not the problem.

If you are correctly distinguishing between generator overload and generator GFI tripping, and generator is in fact overloading, the most likely issue is the ground-neutral bonding.

Some inverter generators do not like having their neutral bonded to ground.  Most inverter-generators have a floating H-bridge AC output so if you measure from hot or neutral to generator case ground you will measure about 60vac (assuming a 120vac generator).  Most inverter-generators have optical isolation for their high voltage DC alternator output to their AC inverter so they will tolerate neutral-ground bonding.

I use an isolation transformer to avoid ground bonding inverter-generator neutral on my Yamaha EF3000ie and provide 240vac split phase to my inverter from 120vac inverter-generator.

You can check generator by itself, unloaded, to see if it works okay if you connect generator's neutral to generator's ground wire. Make sure you select generator neutral and not its hot line output. It will likely be okay with hot to ground instead of neutral to ground, by itself, but this will cause a problem when you plug into inverter input.  Assuming it does works with neutral-ground bonding, then you may have hot to ground bonded instead of neutral to ground connected.  If generator end s connected one way and inverter end has it connected other way (hot to ground on one end, likely generator end, & neutral to ground on inverter end) then you effectively have a short across generator when you connect generator to inverter.  For this situation the generator would immediately overload when plugged into inverter.

If inverter-generator does not tolerate its neutral to be grounded it may show overload immediately when its neutral is connected to ground wire on plug.  Inverter-generators that do not tolerate neutral-ground bonding will usually say something in their manual like 'this generator is not intended to be used for directly wiring to house electrical panel'.