No spark at either plug

[alloyantique]

I have J.D. 345 lawn tractor with no spark at either plug.I have replaced 1 ign.coil and pulser coils.Still no spark.Beside ignition module,what other component is involved in ignition spark?Any help would be appreciated.
Thanks,Mark

 

[reynoldston]

Always isolate the engine from the chassis. This will tell you where to start looking. A wiring diagram is another must to have, its like a road map in a strange big city. I am sure you will get a lot of advice here. A test light to the less but a volt is handy. I have been doing this for years and these are the things I still need and use.