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28hp Kohler EFI engine not staying charged...

Discussion in 'Lawn Mowing' started by ztrguy, Sep 19, 2008.

  1. ztrguy

    ztrguy LawnSite Senior Member
    from NE FL
    Messages: 466

    I have a 28hp Kohler EFI engine that will not stay charged. I have had the rectifier, stator, and battery replaced. It will stay charged for maybe an hour or two of continuous use and it will drain the battery down. Once the battery is drained down the light will come on and it will start to lose power and eventually die. If someone can please figure out how in the world to fix this problem I will give them a prize! Seriously, I've spent over $500 to fix the issue and it still has not been fixed. I need help! Please give me your suggestions. I would greatly appreciate it! Thanks!
  2. cgaengineer

    cgaengineer LawnSite Fanatic
    Messages: 15,778

    Sounds to me like you have a parasitic draw. Take a look at this article for testing parasitic draw. http://www.inliners.org/tech/tech6.html I know you dont have fuses, but you can find out what is draining the battery while ignition is off. Basically you will disconnect the negative battery cable and put a test light between the battery and the cable. Once you have done this you can start unhooking electricals until light goes off. I cannot think of one thing on a mower that should have power all of the time like a radio in a car...except maybe an hour meter.
  3. mcduff48

    mcduff48 LawnSite Member
    Messages: 96

    Try using a test light to see if you have power coming from the stator. Find the voltage regulator and (with the engine running) unplug the lead going to it. Hook the negative clip of the test light to the negative battery post and use the probe to check the white wires going to the regulator. If it doesn't light up, you will need a stator and probably a flywheel. Kohler has had a problem with the magnets epoxied to the inside of the flywheel coming lose and damaging the stator. Be sure to replace both stator and flywheel or you will be doing the same job all over again very soon. I hope this is helpful. Good luck. :usflag:
  4. Richard Martin

    Richard Martin LawnSite Fanatic
    Messages: 14,699

    He has a EFI mower Chris. It has multiple fuses along with a KAM (Keep Alive Memory in the computer). It will always draw power.

    The first thing I would do is see if it is charging. Charge the battery up and then start the mower. Read the voltage at the battery. It should be 13.5 volts or higher. Get back to me with the results.
  5. ztrguy

    ztrguy LawnSite Senior Member
    from NE FL
    Messages: 466

    Thanks for the replies...
  6. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    One other thing,

    Hooking a 12 volt test light to the white stator wires will only blow the test light bulb since the stator puts out 35+ AC volts when working properly.....
  7. tomo

    tomo LawnSite Senior Member
    Messages: 660

    first charge and check battery with a load tester
    2/ check for output from stator windings AC volts refer kohler 4 the spec
    3/ check out put at the regulator [DC] /rectifier turns ac to dc -both r in the one unit at least 13.5 vdc at 3000rpm . Ideal voltage 13.8--14.3
    4/ If output is there u have lost it some where in the wiring on its way to the battery

    nb excessive cleaning with compressed air can cause very small stones to dislodge from behind flywheel and damage stator also .

    magnets come loose

    in many cases charge amperage goes thru the ignition switch ,It eventually burns out the contacts

    system maybe relay isolated from battery and as u would expect a fuse and or fusable link

  8. cgaengineer

    cgaengineer LawnSite Fanatic
    Messages: 15,778

    Thanks you Richard, was not sure how "electric" EFI was on this mower. I know some stuff is electro mechanical without computers.
  9. pugs

    pugs LawnSite Gold Member
    Messages: 3,025

    Why did you replace basically the entire charging system? Why not find the problem and replace or repair that? Probably nothing wrong with all the stuff you replaced. You probably have a wiring issue or other relatively small problem.
  10. ztrguy

    ztrguy LawnSite Senior Member
    from NE FL
    Messages: 466

    The Toro dealer thought it was the rectifier so they replaced it. Once that didn't fix the problem they replaced the stator. And that didn't work either. Thought it may be a bad battery so they replaced the battery. Long story short, $500 later and new parts the problem still exist. I need help!

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