I want to ground a 5500W generator and want to know if I can ground it to the existing
Home ground rod? I understand that I need a #6 copper wire, however the generator
Receptacle does not accept this size of wire, it is to big. Can I use a smaller size wire?

I only use the generator during power outages during the Hurricane season.

You do NOT need a ground rod for a portable generator that is connected via the receptacles on the panel.

Only a hard wired standby generator requires a ground rod.

Just so you know, even if you did connect your genny to a ground rod, it would NOT be doing ANYTHING. A ground rod does NOT "provide" or create a ground.

Most portable generators have a neutral to ground bond in the final (120/240v) side of the wiring.

This genator is not connected via the receptacles on the house panel, it is standing on its
Own and provide the power via extension cords to the refrigirators and some llights as well
As a couple of fans!

Then a ground rod will do absolutely nothing for you.

Thank you very much for the information, I can return the ground rod and clamps.