Hello M.,
Aftermarket carburetors often have a tight linkage end fit that will stump a person. Aftermarket carburetors only claim they will fit, but no mention of working correctly, especially under a load.
Sounds like you are on the right path though.
It is best to set the readings on a portable generator using a Kill-O-Watt plug in tester so you can read the actual Hertz and voltage output. Unloaded usually reads around 61.5 Hertz/ 120-125V at 3600 RPM and drops slightly below when under electrical load. The voltage will be calibrated by the AVR if it is working correctly.
Watch some of the videos by James Condon that I mentioned earlier. It really helps.
Note: The oil is the "lifeblood" of any air-cooled generator engine. Plan on changing it once a year regardless and be sure to give it a "run exercise" under load once a month for at least 30 minutes.
Never trust the engine oil by looks alone, if it turns "black" that would mean serious wear, poor running conditions and neglect. New oil once a season also means more life for your generator and less problems when you need to rely on it in bad conditions.
As the economy has gotten tighter, small engine equipment, especially portable generators tend to get neglected more than ever. The manufacturers bank on people neglecting and abusing them.... Ever notice how retail stores stock up on them quickly when bad weather is predicted? That is no accident.