started dismembering my 125 to sell parts, what do i need to keep for the engine to be able to run?

bike has a bent frame from a crash otherwise id just keep it or sell it whole, but i kinda wanted to keep the engine as its kinda indestructible, so what are the critical parts that i need to keep for the engine to still work? i guess i need to obviously keep the carb and the control unit, but what about stuff like the airbox or the exhaust?