Diagnosing champion generator.

[Annieclover24]

I have a 4000/3500 watt champion model 46514 built October of 2012 generator that last year ran great. I put it up for an extended time so I drained all fuel, changed the oil, removed the plug and put some oil in the cylinder. I also poured an ounce or two in the fuel tank and tipped the generator around to cover the entire bottom. Cleaned the unit and put it on a shelf with a cover on it.
Yesterday working in the barn I wondered if it would take much to get it going. I added fresh gas, removed the brushes and cleand the slip rings, checked the oil and tried to fire it up. Second pull it started and was surging. Let it warm up a bit then applied a 1500 watt load. Still surging but did pull the load. Shut it down and removed the idel jet from the carb and cleaned it. Also shot some carb cleaner in the carb and in the fuel line. Started it again and it was better but not smooth like it should be. With the choke just a tiny bit closed it would smooth out. Okay, no problem, must be a plugged jet and or dirt in the carb. Took the carb off and totaly cleaned it. Put it all back together and same thing, surging and just a little close of the choke and it would smooth out.
Got my can of carb cleaner and sprayed around the carb mounting area and smooth as silk for a few minutes then back to surging. I shut it down again and removed the carb and intake adapter plate. The gasket that is between the engine and plate apparently got dry and had a vacuum leak. Made some new gaskets, put her all back together and now purring like it should. Currently doing a load test on it pulling 3000 watts. The generator is holding 119 volts and 58.6hz. At almost full load I am a happy camper. No load readings are 120.5 volts and 61hz.
I just never thought a gasket would dry out like that and cause problems. Just wanted to post this incase others have a similar issue they may get a place to look for the problem.