Question 480Motor Plants - Assistant Engineer

The correct answer is C) decrease to a slightly lower value. When the speeder spring of a main propulsion diesel engine governor breaks, the engine's RPM will decrease to a slightly lower value. This is because the speeder spring is responsible for maintaining the engine's desired operating speed. With the speeder spring broken, the governor's ability to maintain the engine's RPM at the set value is compromised, causing the RPM to decrease slightly. The other options are incorrect because: A) the engine would not increase to the point of activating the overspeed trip, as the governor is still functional, albeit with a broken speeder spring; B) the engine would not hunt, as the governor would stabilize the RPM at a slightly lower value; and D) the RPM would not remain the same, as the broken speeder spring would affect the governor's ability to maintain the set RPM.