Which of the following pressure values is accepted as the maximum for a compression check on reciprocating engines?

In a compression check of reciprocating engines, the maximum accepted pressure value is typically set at 25% of the standard reading for the specific engine. This percentage is used to evaluate the condition of the engine's cylinders and the efficiency of the sealing components, such as piston rings and valves.

A compression reading that exceeds 25% variation from the manufacturer's standards may indicate significant wear or damage, resulting in poor engine performance or potential mechanical failure. Thus, maintaining the compression variation at or below this percentage is crucial for ensuring the engine operates within acceptable limits and for identifying any necessary maintenance actions.

The reference to 25% as a maximum value is grounded in industry standards and practices that prioritize engine reliability and safety, ensuring that mechanics can assess the engine's health effectively during inspections.