Not too many folks have Generac gensets. Most have Onan, some have Powertech.
We have a Generac NP-75D diesel genset and the main circuit board has a bad circuit on it. I had to re-wire the Pre-heater circuit from the genset mounted start switch to the dash switch as the dash circuit on the board was bad.
If I had time/$, I would replace the board but at around $650, not right now. My fix works and how often am I under the front of the coach and need to start the generator?
One thing I noticed is that the genset will NEVER stay running on the first try. I hold the pre-heater switch for about 20 seconds and then hit the start switch. When it starts, I release both and it promptly dies. When I do it a second time, it stays running. It makes me think that maybe the fuel pump is getting weak or something else?
Sorry...I got off topic here...
If you have to manually choke the genset when cold, is there a thermal valve that is bad? For reference, on a Thermoquad carburetor (440 power!!!!) and some other brands, there is a "stove pipe" type of choke spring. It changes tension as it warms up from the engine running and gradually opens the choke. Of course there are approx. 30 other items/linkages to set that can affect the correct functioning of the carburetor and some deal with the choke linkage.
Perhaps yours just needs some adjustment. How does the choke work? what model of Generac do you have? I can do some research to see what info is available or you can call these guys:
Scwalm & Associates
(909) 591-4341
They are a Generac service center here in SoCal and they have helped me out a time or two.