Generator motor runs fine, not getting electrical power, reset buttons seem ok, has not been run for more than a year

is anything plugged into the gen when you reset it?
If so unplug everything and try again.
If not, it is an internal problem with the inverter.

If the motor runs AND there is no electricity the power regulator modul can be damaged by faultering slide contacts or overload, if there is no circuit breaker protection is to find, a power assembly if there is used or a capacitor damaged.

Check the online support of these generators, or look at this operating video for information:

Generac 5000 watt 6250 surge watt generator running

Probably needs new brushes or a new regulator I would check the brushes first

Sounds like the generator unit (sometimes called the generator head) has overheated and melted the insulation in the windings. This is the same as an electric motor "burning out", and if this is the case, then the generator is toast. If you happened to notice that the lights or fans were getting dim or slowing down before the breaker tripped (without the gas engine slowing down) then this is most likely the case and you generator is toast. But if the output just suddenly quit, then it is possible that some smaller electrical component has failed. In any case, it's not something external that you can easily reset or replace. Sorry for the bad news.

Hello dear, would you consider buying a new generator? Generator Diesel Generator Cummins Generator Volvo Generator Perkins...
If you can start your generator normally, you can analyze the reasons through the following article:
Why Diesel Generator Fail to Start
Simple Ways to Deal with Diesel Generator Failure
Hope it works for you.

they have reset buttons usuall black push to reset

check

avr / brushes if it has them

if not capacitor and diodes on the end of the armature

Where can i obtain a manual for the 5500 gas generator

Reset / tickled? There are resistors and diodes in the end of the alternators rotor (the bit in the middle that spins) If these look ok visually then change the capacitor which is a barrel shaped object usually with 4 prongs on the end. Without a capacitor the genset will not produce a voltage.