I have an Onan 7000 and it surges pretty bad when not loaded. The dealer told me they all surge when not under load. The motorhome I bought was 3 years old and only had 13 hours on the genset. In the last two months since I got it, it's up to 32 hours and running better than ever. Most of the surging is gone.
My previous motorhome had a Generac and it never missed a lick and did not surge at all loaded or not. Wasn't as quiet as the Onan, but sure was smoother.
2005 34' Allegro Bay W22/8.1L
Tiffin Coach Owner's Forum Member