Onan MDKAW

I've heard of false-overfilled issues with Onan genny's oil level. The suggested remedy as I understand was to run with the oil below full, above the add-line, but somewhat below full. Maybe in the lower half of that range. Seems like an easy thing to try...

I think I heard about this Onan issue from an RV guy. Said it was happening for a while, and seemed to be consistent with oil addition to his unit. The high oil level is a component of the unit's safety systems, and there is some question about the accuracy of the dipstick or something like that. Not sure if it's the same unit you've got, but it's what I've been told...

I experienced something similar on an ONAN genset, though I can't remember the exact model.
And it took a while to find out that it was just an unstable contact on the shutoff solenoid.
I can't grant you it's the same issue of course, but I wish you it is, because it only takes one minute to fix it, by tightening the contact.
Thinking to check it was the only tricky part!

My pleasure. Keep us updated on your findings!

How many hours on the unit? I've had this happen on a unit with a lot of hours and heat exchanger never cleaned and with a medium load it would run fine, then another a/c would kick on and it would hit the overheat safety switch and shut down.

The one I dealt with didn't steam......it was a pretty good run from the engine to the exhaust so maybe the steam disappated. After I had the heat exchanger cleaned, 3x the water flow came out of the exhaust. Owner had had the boat 17 years and it was so gradual he never noticed that's all it was pumping towards the end.