Small Engines (Lawn Mowers, etc.): Murray Lawn Tractor does not have any power, murray lawn tractor, spark plug wire

Question
Ben,

I have a Murray Riding Lawn mower (N.A.A.C.P.) that I can not get to start.  I have been working on it for over a year with no result.  I took it to the local repair shop and they couldn't help either.  Here is my situation:
The mower always had a hesitation when starting in the first place, but after it fired there were no problems.  At the end of the year I had to get off the mower to move some debris.  I engaged the metal rod you have to pull up when getting off the mower to keep it running.  I moved the debris and was about to get back on when I hear a loud pop and the mower cut off.  I saw some damage to the spark plug wire (black and melted casing, so I figured it arced#.  I replaced the entire plug wire assembly and put in a new spark plug.  Still now power to the starter.  I then figured it was the solenoid, so i replaced it, again no power.  Long story short, I have replaces all #3) limit switches, main wire harness, clean all grounds where they contact metal, replaced the ignition switch, fuel filter, fuel lines, starter, everything except the positive wire from battery to solenoid, solenoid to starter, ground wire from battery to chassie, and the seat switch wire harness.  I can jump the solenoid and the engine will fire and run for about 30 seconds then it dies.  I have the proper 12 volts required to the solenoid.  I have even taken the old wire harness and directly connected the orange wire to the solenoid to bypass the limit switches and still nothing. Do you have any thoughts before I destroy this mower?

Answer
Michael
Sounds  like you had a short that caused a problem in the wiring harness. have you checked the alternator output? Since you have done a bunch of things and I see you haven't done this you may want to make sure that the alternator is putting out the correct voltage and amps. You also say that if you jump start the solenoid and it will start and then it dies maybe the battery also is bad. I don not know how you are jump starting it are you using a outside source, or the mower battery? If you send me the engine model numbers and any other numbers on the engine I can let you know what the output should be and how to check it.