503 not starting

[Tracer]

Hi Guys,

Hope someone can give me a couple of ideas on how to troubleshoot the problem.

My 503, won't start. Checked the fuel, all OK. I then checked the plugs, found they were quite fouled and replaced them with new ones. Still nothing, I then pulled one of the plugs and found that there was no spark.

I am not sure were to look for the problem now? Checked the Mag switches and they work correctly!

I would like to try and find the problem, before asking Flo. I would like to learn as much as possible, to enable me to troubleshoot if there is nobody available when I fly somewhere.

Thanks,

[Low Level]

Bic Mac had a situation where the wires from the magneto, touched the magneto, and got worn through. This caused erratic firing, and subsequential detonation. Had to replace two pistons.