Probably the safety kill switch. A lanyard with a loop on one end and clip on the other is used for safety reasons should you accidentally fall out of the boat. The loop fits over the switch and you push it up to the closed position. If you pull on the lanyard, it will free itself from the switch lever and in the process flip the lever down which kills the ignition. You attach the clip to your clothing somewhere convenient. Very important in things like bass boats that run at high speeds and you are pretty exposed; unlike something like a cabin cruiser or such.
If you ever have an engine that won't start, may be you have the switch in the kill position accidentally. BTDT
