How do you run compression test?

To run a compression test on an internal combustion engine, first, ensure the engine is at operating temperature and remove all spark plugs. Next, insert a compression gauge into the spark plug hole of the cylinder being tested, then crank the engine for a few seconds using the starter motor. Record the maximum pressure reading on the gauge, and repeat this process for each cylinder. Finally, compare the results to the manufacturer's specifications to assess the engine's health.