Hunting and surging under load indicates a problem with the __________.

Hunting and surging under load often point to issues with the carburetor system. The carburetor is responsible for mixing air and fuel in the correct ratio for efficient combustion. If the carburetor is not functioning properly—such as due to a blockage, incorrect float level, or an improper air/fuel mixture—it can cause the engine to struggle when more load is applied. This leads to fluctuations in engine power, which manifest as hunting (rapid variations in engine speed) and surging (intermittent increases and decreases in engine power).

The other options, while they could lead to other issues, are less likely to directly cause the hunting and surging behavior as described. For instance, while a fuel pump can affect engine performance if it fails to deliver adequate fuel, it often results in more consistent power loss rather than the erratic behavior described. Similarly, the governor system regulates engine speed but generally does not cause the erratic variations unless there are specific malfunctioning components. A choke cable adjustment primarily affects the mixture at startup rather than under load conditions once the engine is warm and running. Thus, issues with the carburetor system are the most common cause of the symptoms noted in the question.