Onan 5.5HGJAB-901C generator is surging?

The main problem that causes surging is a dirty carb. What happens is the gas that we have now is not real good the shelf life is only around 30 days and it starts to go bad, so when gas sets in the carb and it is not being used it starts to gum up the carb and dirt gets in the fuel passages and it slows the flow of gas to the engine and it causes the surging your having. The carb will need to be removed and cleaned good and the fuel passages will need to be cleaned out with a fine wire.

----------------