Spark Cutting Off

Discussion in 'Mechanic and Repair' started by MARK 30, Aug 2, 2004.

  1. MARK 30

    MARK 30 LawnSite Member
    Posts: 1

    I AM WORKING ON A SCAG LAWNMOWER WITH A KOHLER 22 HP ENGINE. WHEN YOU START IT UP, IT WILL RUN FOR APP. 2 SECONDS, AND THEN DIES, I GROUNDED THE SPARK PLUG AND NOTICED THE SPARK CUTS OFF. COULD THIS POOSIBLY BE THE COIL, OR THE ELECTRONIC IGNITION? IF YOU HAVE ANY SUGGESTIONS IT WOULD BE MUCH APPRECIATED.
     
  2. fixer67

    fixer67 LawnSite Silver Member
    Posts: 2,100

    It is the key switch. I have had this to happen before. If you check the wiring schematic you will see that the Smart Pak ( that block box mounted on the fan cover) must have 12 volts to run. If you check you will also be losing power to the fuel solenoid when you let off the key switch. There are TWO power routes to the fuel solenoid and Smart Pak. One is on the start circuit and the other one is on the run circuit. There is a diode set in the Kohler wiring harness that allows this to happen. The chances of that diode set going bad are 1 in a Million. The must likely cause is the key switch or the harness plug where the Kohler wiring harness mates to the machine wiring harness. What is happing is you get power to the Smart Pak and fuel solenoid on start up but as so as you let go of the key and the starter drops out the run circuit does not kick in. To test for this hook up a test meter (or light) to the wire going to the fuel solenoid (it is the easiest one to get to) and turn the key to the RUN position and when you can get power there you should have it to the Smart Pak. I have had this happen on Walkers a few times. Good Luck
     

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