Small Engines (Lawn Mowers, etc.): Sears lawnmower wont shut off, spark plug wire, crafsman

Question
I have a Sears Crafsman lawn tractor with a Kohler engine, 17.5 hp.  Model #917.273180  It is two years old.  The engine will not shut off when I turn the key off.  I bought a new ignition switch but this did not solve the problem.  I pull the spark plug wire off to shut the engine off.  I noticed the headlights work occasionally, don't know if this is related to my problem.  I sure would appreciate any help that you may suggest.  Thanks,  Dave  

Answer
 Hello Dave:

 The Coil Wire to the Ignition Switch isnt Connected to the Coil or it has a Break in the Wire. Start at the Engine and Follow the Coil Shut Off Wire Until you Find the Break or Replace the Shut Off Wire Comletely. If you need to View the Mower, go to http://www3.sears.com/ and Follow the Direction to the Page that has Your Mowers Diagram On It. If you Cant find the Diagram, let me know and I will give you the Complete Steps to get to the Diagram. Hope this Helps. Let me Know what Happens, Please.

 Good Luck

 Respectfully

 John