Small Engines (Lawn Mowers, etc.): B&S wont start when hot, spark testers, spark tester

Question
Murray mower with 17hp briggs won't start when hot. Replaced plugs. Model 42A707 type 1653 01.Starts easily when cold but will not start for an extended period of time after running. Is getting fuel. What now?

Answer
You need to check for spark when it will not start.  You can purchase in-line spark testers at most any auto parts store.  Check for spark first, then fuel and finally compression.

You may also try removing and installing new plugs when the engine stops.

Igniton coils sometime cause this problem.  When they get hot the insulation may be breaking down and preventing spark.  I would try an in-line spark tester before replacing the expensive coil.

Let me know what you find.
Eric