Rigid Generator w/ Yamaha Engine Wont Crank

Hey guys hoping you can help. I just bought a rigid generator with yamaha 37o engine. It ran perfect for 10 or so hours. I left it outside one night not expecting rain and it came a down pour. The tarp I had over it blew off and generator I know got pounded on. I let it sit for a couple days and oiled the areas I thought might rust that next morning. After a couple days I tried to crank it and it would crank but rev and almost die then rev up again and then die. Thinking water must have gotten in fuel tank I drained the tank and put new gas in it. The generator started up and ran good for a couple hours while I was working. Right when we were quitting for the day it started to die like it did when we were starting it after the rain. I thought it was bc it was running out of gas. So today I go back to work and fill the tank and try and start the generator and the something happens. Drained the fuel again and it did not help. Checked the spark plug. Cleaned it and it started right up and ran for a minute or two before dying again. Tried starting it many times with no success. During this time I went and replaced spark plug. So while starting it I tried moving the throttle arm and when I did it started right up and then found its idle and idled perfect. Ran it for 1-2 hrs and was good. I don't know if it is a carb problem, governor problem or some electric problem. This is a generator for my RV so I can't have it go out on us while out there in this heat. I would really appreciate you guys knowledge and help. Would like to try and fix it myself before taking it in. Let me know what you guys think. I appreciate it.

Does it have a low oil shutdown, and did you check the oil level. It has symptoms of oil that gets too low when running causing shutdown.

Yes I checked oil and it was good. Today I pulled the carb pan and saw a little trash at the bottom. I dumped it and it started right up like it used to. I am thinking there was some trash in carb and somehow it either came loose and settled at bottom of carb or ran through the engine, cause its back to running good. Hoping it lasts. Thanks for your reply though.