Small Engines (Lawn Mowers, etc.): no spark, feeler gauge, starter fluid

Question
my father in law has a john deere riding mower model 1538. I think it is a 1997 model. We cannot get spark to the plug. We replaced the solenoid and the electronic module that has the wire leading to the plug. We changed the plug also. He thought it wasnt getting fuel so he sprayed starter fluid into the carb but of course, nothing happened. I made sure the gap was right with the feeler gauge that they give you for the module against the flywheel. What could the problem be?

Answer
What engine is on the mower?  If you have a Briggs engine, dis-connect the small wire connected to the ignition coil and check for spark.

My guess is a safety switch is preventing or grounding the spark.  Have you check the safety switches to see if they are working correctly?

Eric