Gather a compression tester, spark plug socket, ratchet, and battery charger if needed
Warm the engine to operating temperature if possible
Disable fuel and ignition systems
Remove all spark plugs
Open the throttle fully
Thread the compression tester into the first cylinder spark plug hole
Crank the engine for several revolutions until the gauge stops rising
Record the reading
Release the pressure from the tester
Repeat for each cylinder
Compare all cylinder readings to each other and to the manufacturer specification
Perform a wet compression test if a cylinder reading is low
Reinstall the spark plugs and reconnect fuel and ignition systems