Under no load RPM sags and the voltage sags from 120v to 112v and then comes right back up to 120v with RPM increase. Under load the same thing happens but with a smaller range 115V to 110V. Just had new crank seals installed by a Generac shop with 30 years exp. Prior to service it had a 1 or 2 volt fluctuation no load and stable inder load.

Electrical Supplies - Guardian - Rv Generator 4800 Watt, Gasoline, Primepact 50G