Small Engines (Lawn Mowers, etc.): White Hydromatic Lawnmower, briggs stratton engine, briggs stratton

Question
I have a White Hydromatic Riding Lawn Mower model #GT-185OHV 18 HP V-twin OHV with a Vanguard Briggs & Stratton engine. Can't get it to turn over by itself and start.  Will only turn over if 12 volts are fed directly to starter.  Have replaced battery, ignition switch, starter, solenoid, and tested neutral safety switches.  If 12 volts are fed to starter it will turn over, but not fire.  Any ideas?

Answer
Hello Ernie:

Remove the Shut Off Wire from the Coil and Jumper Straight to the Starter. Does the Engine Start and Run? If the Engine Runs, then If None of the Safety Switches are Bad, then there is a Problem with the Wiring Harness. The Numbers You Sent are the Series Numbers. I Require the Mower Model Numbers, Please. With these I can Locate the Proper manuals and Better Assist you. Thanks.

Respectfully

John