Restoration of a HYUNDAI portable generator with a sharp knocking noise

I found this portable generator from a used items sale for a relatively cheap price. It ran poorly even after cleaning the tank and the carburetor. After running for couple of minutes, it began to make a sharp knocking sound. Here I'm discovering what's happening inside. Enjoy it.
Edited with: Adobe Premiere Pro CC 2019
Recorded with: Nokia 5, Huawei Y9

[@vicosee4439]

Did you replace conecting rod ?

[@juniooliveirabrasil7454]

Brasil