there was a point (dont recall exactly when) that cummins/onan replaced or removed a inline fuel filter and when you did a service on them they would do what you are describing. I can't remember what part was replaced, when or if you simply removed the old one or replaced it with a different part number...I keep thinking it had to do with starving the carb of fuel for some reason...Sorry its been a few years since i had to deal with that...I didnt find out about until one of my friends went into the Onan dealer and spoke to them...
