Must be something in the air. My Scag started the same thing yesterday.
Was running and mowing and just died. I noticed 2 days ago it would sputter occasionally. Kohler, 24 hp, air cooled. Will start, but dies immediately. If I hit start, it will fire again and run a couple more seconds (I know, hard on the starter) so I'm sure it's an ignition/spark problem. I did notice the couple seconds it runs the amp meter doesn't show any charge.
I was wondering if the ignition fires from the battery at start and the stator at run. If so, a bad stator would make perfect sense.
Checked for bad wires, fuses, and relays all seemed ok. Checked the key switch, even plugged in another one, no luck.
Any suggestions, or other ideas? Thanks.