Sorry, your optional info doesn't show up right away and I didn't have it on the screen when I asked about it being a Honda.
Personally, if someone charged me $1300 for a $300 engine I would have a serious problem with them.
The Greyhound is simply a Honda clone made in China. Many, many different label names are XXXXX XXXXX them, but they're all the same engine with a few different levels of machining done. This is the Harbor Freight version and is okay, but is nowhere near a Honda.
The first thing I would try is overfilling the oil a little bit. These don't have the best electrics in the world and often the low-oil switch malfunctions.
Quite honestly, I wouldn't spend a dime on this engine. It's not that they're not decent engines, for the money they are. But this should be under warranty and this is certainly a warranty issue. If you do try to do much work on it, you will violate the warranty.
If you do decide you'd like to work on it and you try overfilling the oil a little bit with no success, then let me know and we'll figure it out. Thanks, PK.