Question

Which is the least likely cause of an engine to hunt and surge at top no-load speeds? A lean air/fuel mixture An incorrect spark plug heat range. A blocked carburetor bowl vent All of the above.

Answer 1

A blocked carburetor bowl vent

Step-by-step explanation:

Engine hunt is defined as the continuous variation in rpm of the engine. It can occur due to various conditions and abnormalities in the inside the fuel injector pump.

In ideal situation, amount of fuel given to the injector is fixed but in some cases such abnormality arises hence rpm get changed.

Hence of the options available, a blocked carburetor bowl is the least likely cause for engine hunt.

Answer 2

I would say that the answer to this is the last option: ALL OF THE ABOVE. A lean fuel or air mixture, incorrect spark plug heat range, and a blocked carburetor bowl vent would be among the reasons of an engine to surge and hunt at the top no-load speeds. Hope this answer helps.