When checking the governed engine speed, what should be the acceptable range of rpm when compared to the new governed engine speed?

The acceptable range of governed engine speed is often specified in terms of a certain number of revolutions per minute (rpm) to ensure that the engine operates efficiently and within its design parameters. When determining this acceptable range, it's important that the engine does not deviate significantly from the new governed engine speed, which is set by the manufacturer and optimized for performance.

A range of 50 rpm is typically considered reasonable because it provides a balance between allowing for slight variations that may occur due to engine wear, ambient conditions, and other mechanical factors, while still ensuring that the engine functions effectively within its designed capabilities. This range helps in identifying any significant deviations that could indicate maintenance issues or system malfunctions.

Lower ranges, such as 10 or 25 rpm, may not allow enough tolerance for these variations, while a higher range like 100 rpm could indicate a significant issue with the engine that might impair its performance or safety. Therefore, choosing a limit of 50 rpm strikes an appropriate middle ground conducive to reliable engine operation.