Final answer:
The top no load governed speed of a model 126802-0421 engine cannot be determined without specific engine specifications.
Step-by-step explanation:
The top no load governed speed of a model 126802-0421 engine can be determined by referring to the engine's specifications provided by the manufacturer.
Without access to specific information on the engine model mentioned, it is not possible to provide the exact top no load governed speed. Therefore, option D. None of the above would be the correct answer without additional information.