Mary, you are using it exactly as I do. It is the perfect tool for a compression test (leave the key off in that instance, you are ONLY spinning the motor for the compression gauge & need no ignition power).
If you actually want to start the motor, but be down below to observe as Dave N. does, you would hook up the starter switch, go to the cockpit and turn the key on, then go below and pull the trigger to start the motor. My starter trigger is just a couple cheap alligator clips on the end..I do not leave mine connected to the starter when I am done using it.