LOL that's been around here a few times. That's a Russian brand chainsaw that is still in production. They are known to very dangerous to cut logs with because of their design, they are the king of saws for major kickback.
I've seen them on Ebay. They have an internal oil filled gearbox reduction and cent clutch and are around 49 cc I think. Seems like they would be great for bike engines. By the looks of that dark ring real close to the drive sprocket, I'd say that the bar has a hole and the chain is stationary.
Definitly a safer use of them than sawing