Where can I get lower cost onan parts?

[jobguy]

I have an Onan Generator, Emerald 4000, 1992 in a 1992 Winnebago Adventurer. Are there part sources other than Onan/Cummins for a Voltage Regulator and or Circuit Board? Their prices seem very high of parts that should be common. Or, can I dumb this thing down, get rid of the circuit board and still have it run? I have also thought of replacing it with a Honda generator just to save money on replaceable parts.
Are there onan used parts anywhere?
How can I test the voltage regulator to see if it is good?
Thanks
Job guy

 

[jlc2]

I used a company called ASAP (http://www.partsfortechs.com/voltregulators.htm).  They had great prices and quick shipping.  What problem are you having with your 4000?

Jay