My Pa in law bought a generator and some other things off a truck a few years back, brand new, wrapped in plastic stuff, supposedly US made, but had China engines on all of it. I think it was just assembled in the US with the China parts. Anywho, we filled the generator with gas, and oil, it fired right up. He used it two or three times that year, then it sat unneeded for a year or two. We were expecting some bad weather recently with possible power outages, so he decided to fire the generator up and get it ready. Well, it wouldn't start at first, dead battery. After a while, he called me to help him. I assumed he had done the basics, fill the gas, check the oil, check the gas shutoff valve. He hadn't.
To make a long story shorter, in about 5 minutes I had it running. After running about 5 minutes, we had the rod out the side of the block!
I then checked the oil, thought he had done that earlier but hadn't. it overran the port and poured out, and smelled like gas. Last time he had ran it, he didn't cut off the gas valve, while it sat gas slowly filled the crankcase. I had heard of this happening, but the first time I ever actually had it happen. That is why my small engines get the smell test now before I try to start them.