Hi Thanks for your reply
Here is the schematic, I also posted some pictures of measurements made with my cheap scope
The voltage scale is on the bottom left side
The high voltage wire is the green one, the signal wire is the red one
The "cranking disconnected" picture shows the measurement across the green wire, disconnected from the coil during the engine start.
The "high voltage connected" shows the same wire, but with the engine running and the coil connected.
The voltage scale for the above is 80v for each row, the 0 is located at the central row.
The "pickup connected" and "pickup disconnected "show the measurements across the red wire, with engine running and engine starting respectively, here the voltage scale is 1 v for each row.
I need to find a way to stop the engine for a while for a rev limiter, and I'd like to find a solid state solution. Maybe it's better to work on the low voltage side? (the red wire)
I tested some commercial rev limiter, but they short the high voltage wire to ground to stop the engine, and sometimes burn the coil inside the generator.