Please help troubleshoot my old Silver Eagle! No spark.

Last week my silver eagle started acting stupid.
I shut off the clutch switch to pick something up and it wouldn't engage again after that.

So I keep mower running while I ride around spraying weed killer.

When I try to park the mower it shuts down any time I put on the park brake.

I bought a new pto switch and installed it. I can hear the clutch engage when I pull the switch so I'm good there.

So now the engine just turns over with no spark. I'm assuming that a safety circuit is...

Please help troubleshoot my old Silver Eagle! No spark.