pirlbeck wrote:
marcsbigfoot20b27 wrote:
I have a 2500 LP Onan also (Year 2000, maybe spec K?). 6 months ago it was hard to start, was surging badly at no load and had trouble managing a sudden load.
Found by spraying carb clean on the air filter that it was running lean.....idle would smooth right out.
Ended up yanking the demand regulator, getting a rebuild kit on Amazon for ~$60 and using only the diaphragm.
Now it idles normal and runs perfect under load or not.
Would you have a part number of the kit you bought? How were you able to determine that it was the correct kit for your generator?
Thanks!
Mine had a Garretson SD regulator with electric prime. It is possible the prime adjustment knob is in too far causing rich mixture.

The reg itself is also adjustable, the spring tension.....yours could be weak.
Impco regulator kit