Small Engines (Lawn Mowers, etc.): John Deere 130, regulator rectifier, lawnmoer

Question
This lawnmoer ran fine and just shut off. I replaced the coil because I had no spark. I still have no spark. Could it be the Rectifier/Regulator? I noticed the white wire that is hooked up to the coil is grounded when shut off. But that connection is grounded anyway. I am confused can you help?

Answer
It is not the regulator/rectifier. No way, no how, not possible.  Unplug the white wire you were talking about.  Follow it through the tractor.  It will go to the brake switch, pto switch and ignition switch.  It will not go through the seat switch.  You have to test these 2 switches and find the lemon.  I'm betting brakes at 2-1.

The white wire on the tractor side of the harness is grounded when the switch is off.  It is an open circuit when the switch is in the run position.