It's likely a Chinese clone engine of some sort. It resembles a Mitsubishi and or a Maruyama engine. The carburetor reminds me of a cloned Walbro carburetor, as the genuine ones generally have a smoother more polished finish.
I know it LOOKS like a Walbro carburetor.That is a Walbro carb. Carb kit # is K20-WYL