To use the compression tester, you will need to first warm up your engine to operating temperature. Then, remove the spark plugs from the engine and screw the spark plug adapter hose into the spark plug hole. Hand tighten only - DO NOT USE A WRENCH. Next, crank the engine for at least four compression strokes or until the pressure stops rising on the tester. Repeat this process for each cylinder. To disable an electric ignition system, disconnect the electronic ignition module or remove the primary battery terminal from the distributor cap.