What are possible causes of engine surge?

Engine surge can occur due to a variety of factors that disrupt the normal operation of the engine's fuel delivery and air intake systems. In this case, the selection indicating both carburetor flooding and a governor spring hooked into the wrong hole correctly identifies two significant issues that can lead to an engine surge.

Carburetor flooding results in an excess of fuel being delivered to the engine, which can overwhelm the air-fuel mixture balance. When the mixture becomes too rich (too much fuel compared to air), it can lead to unstable combustion and surging, where the engine's power output fluctuates erratically instead of maintaining a consistent performance.

Similarly, if the governor spring is hooked into the wrong hole, it can affect the engine's speed regulation. The governor is responsible for maintaining a steady engine speed by regulating fuel flow based on load demands. If the spring is positioned improperly, it can cause fluctuations in engine speed, leading to surging as the system struggles to stabilize the engine power.

Therefore, both improper carburation due to flooding and the misconfiguration of the governor spring contribute to the phenomenon of engine surge. Recognizing this allows for targeted troubleshooting, ensuring that both conditions are addressed to restore the engine's performance to normal levels.