Small Engines (Lawn Mowers, etc.): Sears Tractor Mower has no spark, briggs stratton engine, briggs stratton

Question
Hi, I have a Sears tractor model number 917.259572 with 19.2 HP Briggs & Stratton engine model number 42E707.

It was running fine, then turned it off and can't get it to start again.  There is no spark.  I replaced the armature-magneto (part no. 394891).  I cleaned the surfaces of the springs under the seat to make sure they are contacting.  I unplugged the plug under the seat (is this a safety switch?) and put a wire in both sides of the female plug but still no spark.  I don't understand how this switch works because the switch is in a plastic housing that doesn't touch any metal.

Anyway, I want to test the other safety switches, but don't know where they are and can't find them in any logical place related to the blade engage or brake mechanism.

I also cleaned the 30amp fuse, but that didn't do anything.  

Thanks for any help you can offer.

Answer
The best method to find the switches is to just follow the wiring harness to each switch.  There are not that many wires and should be 3 to 4 safety switches.

Do you have a multimeter to test the switches?

http://www.searspartsdirect.com/partsdirect/part-model/Craftsman-Parts/Riding-mo

There should be one small wire connected to the igintion module.  Dis-connect the small wire and re-check for spark.  If you have spark with the small wire dis-connected from the igntion module then you know the module is good and you must have a safety switch or shorted wire.

Let me know if this helps.

Eric