Suggest you add the full model number. Last character is Spec Code. Then ask the moderator to move this to Tech Issues. Sample of our tag:

So this genset is commonly known as "4KY Spec K." The numbers in between indicate features, when and where made, etc. 4KY-K is the key information.
Do you have a Service Manual? Some of the guys here have links to download one. I might be able to help but web crawling is not my strong suit.
We have a 31-ft Class C with a 15000-BTU A/C and a residential microwave. The 4KY will NOT reliably run both. It may be because the circuit breaker on the genset is weak. Haven't gotten that far into troubleshooting. It's a 30A Breaker on the SIDE of the control panel, on the generator end. Have you found it?
These gensets won't grab the load right after starting. There's about 30-seconds while it must be checking to be sure its voltage, frequency, etc are OK. Then it applies power to the output wiring. In your case the outlet you plug the shore tie into.
Did this problem just develop?
See if you can get into some troubleshooting charts.