onan 4k generator stopped

Onan uses a LATCHING RELAY that keeps power going to the fuel pump and ignition. This system is BYPASSED when the starter is spinning. A bad low oil switch or other safety SWITCH FAULT can cause these symptoms, a bad latching relay or connectors. You need to troubleshoot.

could be a gen issue. The manual says slip rings, brushes a possibility. I'd take it to cummins

Mine runs fine as long as the start
Button is held in. Don't think carb.
Anything else scares me.
Could it be a loose connection?

Mine would start but die when the start button was released. Carb was varnished and when the choke would pull the throttle all the way open it would stick, over rev and shut itself off due to high rpm & voltage. Cummins diagnosed it, replaced carb $433 out the door. Very pleased with their service. Only charged me 1 hr labor for diag & R&R. Those little carbs are pricey. $285.00. Good luck. I should have done a better job. This thing sat for 4 yrs prior to me buying it. Now it's Seafoam every fill along with staybil.

They said it was scheduled with the tech @ 2pm and I picked it up @ 3. Can't complain about that. This was @ Cummins Rocky Mtn in Phoenix.

Mine does the same thing. Got a app
With a Onan dealer. Will know then.
They told me it is a symptom of no
Power.

Is this a 4 ky what spec.

Sounds like your fuel filter is plugged. Or, maybe your fuel tank is at 1/4 and it's trying to slurp what fuel it can.