Cessna 1 #1 Posted August 11, 2018 (edited) Today I had some time to start the old 312-8. I charged the battery box, sprayed some carb cleaner into the carb and fired up the engine. It fired right up. I had connected a wire connected to the negative post of the battery. I turned the key off but the motor kept on running. Then I touched the ignition switch and the engine quit. I tried it several more times and each time the engine would stop when the wire contacted to the switch. Does this mean that I need a new switch? Edited August 12, 2018 by Cessna Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,444 #2 Posted August 11, 2018 You are touching the (-) negative ground wire to the metal body of the switch? and it quits? Sounds like you have magneto ignition and the body of the switch is not grounded. The switches have a 5-terminal connector over the business end and there is a 6th terminal off to the side that should ground the body of the switch. I doubt the switch is at fault. Clean up the ground connections and you should be good. Click on the picture and again on the next page Garry 1 1 Share this post Link to post Share on other sites