I have a 912ULS in my Speedster.
The ignition switch is key operated with off, left, right and start. On the last flight, on shut down, the off position would not shut down the engine. the RPM would drop to 500 then cycle back to 1000. It would continue to do this, so I had to shut off the fuel to stop the engine.
I suspect the switch is gone bad. Am I on the right tract or could something else be causing the problem