Small Engines (Lawn Mowers, etc.): Honda Harmony 2113 electrical, aviation electrician, honda motorcycles

Question
My tractor honda harmony 2113 hydrostatic has been sitting in the garage for about 3 months untouched.  I went out to start it today for a lawn project and it will start and run with the start switch in the start position, but when let go to the run position it immediately shuts down.  I have had this problem before and taken it to the local lawn mower repair shop and they chased and chased wires and found a bad wire. Could it have possibly happened again, that same wire gone bad?   I have electrical experience, 12 years navy and army aviation electrician and have a ohm meter so I can read out the switches, just don't have a schematic to know what I should be reading. Any suggestions before I have to take it to the shop for an expensive repair?

Answer
It could be the same problem but that would lead me to believe the wiring in general is not the best.  I have a couple of Honda motorcycles and they are great products but Honda does not do as good as job with the electrical as other manufactures.

I am guessing a safety circuit or wire is shorting the ignition system to ground when the key is in the run position shorting the primary side of the ignition coil.  

I would get an inline ignition tester and have a helper start the mower while you watch the inline ignition tester.  If the spark disappears when the key is in the run position then you know the ignition system is being shorted to ground.

Honda schematics can be difficult to find but I'll check the net.  In the mean time you can use your meter to check the safety switches, most are basic open or closed switches.  You can also measure to see if any of the safety switch wires are shorted to ground.

It will probably take sometime to track down the problem so be patient.  I forgot to metion to check the key switch as well.  You should be able to ohm it out as well.

Eric