Start the aircraft's engine. Run the engine until the oil temperature is in the "green" range.
Shut down the engine. Remove the engine cowls to allow engine access.
Remove all the spark plug leads with a 3/4 inch or 7/8 inch wrench.
Remove all top spark plugs with a ratchet driver and a 7/8 inch deep socket.
Obtain an aviation compression tester from an aviation supply company or from your local aircraft mechanic.
Perform a compression test of all cylinders. Follow the instructions for the compression tester's operation. Record compression values for all cylinders. Compare the readings with minimum acceptable values listed in your engine maintenance manual. Acceptable compression readings ensure that exhaust and intake valves are not leaking. Good readings also mean piston rings are not leaking or broken, and there are no cracks in the cylinder head.
Reinstall all the spark plugs. Torque each plug to 360 inch-pounds.
Reinstall the spark plug leads. Tighten each lead snugly.
Reinstall the engine cowls.
Research and record your engine's performance data. The aircraft's pilot's operating handbook, or POH, includes a table entitled "Power Plant Limitations." This table lists data for minimum and maximum oil pressure, maximum oil temperature and static revolutions per minute, or RPM.
Start the aircraft's engine. Taxi the aircraft to the airport's run-up area. Verify that your airport permits an engine run-up at that time and location. Many airports strictly regulate ground-based full-throttle engine run-ups.
Set the aircraft's parking brake. Gradually push the throttle to the "full forward" position. Record the aircraft's tachometer reading. Compare the reading with the static RPM value recorded from the POH. Compare the additional data to readings observed on the engine's instruments. The engine is performing to design specifications if all observed values are within the ranges noted in the POH.
