Small Engines (Lawn Mowers, etc.): Briggs 31P777 cranks but wont start, spark plug wire, safety switches

Question
QUESTION: I have a craftsman mower with a B&S Model 31P777 Type 0348E1 18.5 Intek motor.  The engine would not start running again after I ran it for about 5 minutes without the blades (I was driving it to the shed) and I shut it off at the key.  I have since replaced the coil, fuel filter, and spark plug and can still not get it to start.  It will crank, the flywheel will turn, everything else (safety switches) seems to be good but no spark.  I'm not sure if there is something else I need to check that would prevent it from starting.

ANSWER: Start by accessing the ignition coil and dis-connecting the small wire connected to the coil.  Check for spark.  If you have spark the coil is good and you have a safety switch problem.

NOTE:  The engine will not shut-off with the key switch if the small wire from the coil is disconnected.  You can stop the engine by pulling/disconnecting the spark plug wire or by choking the eninge until it stops.

Let me if you have spark with the small ignition coil wire disconnected.

Eric

---------- FOLLOW-UP ----------

QUESTION: Eric,

I disconnected the small wire and tried it, still nothing.  I purchased a replacement coil, hooked it up, still nothing.  I purchased and used a spark tester from both of them from a local auto parts store and there was no spark from either the new or old coil.  Just a bad coil?  That's what I'm thinking...Thanks for the input.

Answer
It's possible but two bad coils in a row?  Do you have a volt meter or multimeter to see if there is any power on the small wire that connects to the coil  You do not want any power on this wire, no power with the key off, on, or in the start position, NO power at any time.


I have never had flywheel magnets wear out so this is not a very probable casue.  This just leaves the coil...but two in a row?

Have you checked with a local repair shop to see if they can check the module?  I have a tester that can simulate the flywheel and verifies the condition of the module.

I hate to say go buy a new coil, they're expensive, but that's about the only part that can be bad if you have the small shut-off wire disconnected when you check for spark and don't have any spark.

Eric