Model #20371 FWD with Kohler 6.75 cc starts first time every time, but when I stop for a 15-30 minute break (it's a big yard) the mower won't start back up. I clean the spark plug, open the gas cap, but nothing works. An hour to 90 minutes later it starts right up again on first try. Theories anyone? Yeah, I know, don't take a break.....that's my only current solution!
Replace the ignition coil and see if that solves it. A new ignition coil can be found online for less than $25. Here’s the diagnosis and install procedure.
I always try to diagnose the problem before throwing money at mowers replacing perfectly good parts & muddying the waters .
When the mower stops, pull the plug out & ground it
Pull the starter cord and see if you have a spark.
If no spark then remove the blower housing and pull the kill wire off the coil & try again
Still no spark = duff magneto
While they do some times fail when hot & work fine when cold, usually it is an all or nothing affair.