Originally Posted by azpete
i have had this problem a few times, till i figured out that the oil was thinning out to the point, the oil pressure sensor on the generator wasnt working. try changing your oil to 20w50 oil. i know this has worked for me. i live in arizona and travel in 120 degree weather a lot. after changing the oil, problem went away. it may be something else, but this is worth a try.
Yes, that's what I was wondering? Stepping back into the 70's when people (and oil companies) were still messing around trying to figure out these multi grade oils, we had a HECK of a time with those oil pressure sensors (or the oil, whatever). Sometimes the oil was so thin/switch so whipped, that they would only run with the start switch held in the start position because they weren't building enough pressure to stay running on their own, even when at room temp!! So azpete's thoughts came to my mind when reading the OP's post as well. We used to put straight 30 wt. in them to fix it back then.
Regarding the expensive Onan pumps, isn't there a 16.00 (don't quote me, maybe they're 25.00) or so generic pump that's a direct bolt in replacement for them?