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kawasaki -no fire= deere lx172

Discussion in 'Mechanic and Repair' started by echoman8, Jul 26, 2008.

  1. echoman8

    echoman8 LawnSite Senior Member
    Posts: 293

    I bought a used lx172 deere lawn tractor with a fs420v as10 kawasaki motor (14hp). It has no fire. I am a small engine mechanic, but this one has stumped me so far.
    The flywheel key is good. The keyways on both the crankshaft and the flywheel are good.
    I replaced the coil (magneto) and electronic ignition (ignitor/excitor) with new, then I tested with a spark tester many different ways:
    1: Kill/ignitor wire removed from coil.
    2: Kill wire on coil, but wire from ignitor to ignition switch disconnected.
    3: Did tests with coil spade grounded to see if it was a "ground to fire" coil (like some old OMC coils).
    4: Tested with white wire grounded before the ignitor and coil. This wire was disconnected from the ignition switch when tested.
    Actually, there is a miniscule amount of fire (not enough to ignite fuel in motor) when kill wire is disconnected from the coil.
    Fuel --- I have primed to test (through carb and put fuel in cylinder)
    Compression ----- 90 psi
    Does the white wire going from the ignition switch to the ignitor(electronic ignition) and then to the coil require some voltage to produce ignition in this motor? Has anyone ever had to change the flywheel magnet/s or flywheel?
    If anyone has encountered this problem, please advise.

    Thanks, Dennis
  2. kawasaki1

    kawasaki1 LawnSite Member
    Posts: 108

    find the flat 3 wire connector running from the engine to the wiring harness. unplug it. you've now isolated the ignition from the machine.

    check your spark plug cap. some of them had a resistor built into them and they go bad sometimes.

    make sure they gave you the right coil.

    i had a lx come in the shop with the same condition.

    customer had installed a new style coil that has the ignitor built into it. they will not work on an external ignitor equipped engine unless you change the flywheel.

    compare the old coil to the new. if the new one has a square looking end where the ground terminal is it won't work.

    make sure the coil is installed in the proper direction.

    all the white wire is is a ground once it leaves the ignitor. if any kind of voltage is applied it will fry the ignitor and coil.
  3. Phil G

    Phil G LawnSite Senior Member
    Posts: 843

    Hi Dennis, I've not worked on any of these, but I figure small engines from different manufacturers have too many similarities.
    Is it electric start only? Or is there a recoil start as well. Like you I'd disconnect all the wire to the switch and any cutout so it's a bare coil/ignitor.
    Is the coil/flywheel gap good, set to thickness of business card. Make sure both pickups on the coil are equally spaced. Don't forget these electronic units need the equal of 300rpm to spark enough to fire the fuel. Is the starter lazy? If there's a recoil fitted use this to spin the engine.
    Now I'm off to think of other possibilities.
    Good luck Phil :)
  4. echoman8

    echoman8 LawnSite Senior Member
    Posts: 293

    First, thanks for your help.

    I disconnected the wiring between the key switch (ignition switch)and the electronic ignition (ignitor/excitor). The disconnect is just before the excitor and this isolates the excitor and the coil/magneto.

    I removed the spark plug cap (exposing a spring device for the spark plug ). I found no indication of a resistor.

    The coil I purchased was from Tulsa (Oklahoma) Warehouse. The parts are probably from Stens. The cosmetics are the same (no square receptical). The fire/lack of fire is the same with the old coil and ignitor as with the new coil and new ignitor.

    The Ignitor is Deere #131398. The current # after 73484, 128800, & 131198.

    I installed the coil in the correct direction.

    The white wire is the wire I disconnected first. I disconnected it between the Ignitor and the key switch (ignition switch). This totally isolates the igntor and the coil from all other electrical connections.
    _____Just for grins, I modified a 12hp briggs coil to mount on the Kawasaki. I got the same result: Extremely weak fire. I did not connect the excitor to the briggs coil. I realize the magnet setup is not similar on the flywheel of a bs and a kawasaki.

    In my experience, It is not likely that I get the same identical result from a defective part. So, I trust my new coil and new ignitor.

    Just to recap other. I pulled the flywheel. The key and keyways are good. The difficulty of removing the flysheel assures me that no one has removed it recently.

    Thanks again

    --------Remember any advise that may be helpful is appreciated ---------

  5. echoman8

    echoman8 LawnSite Senior Member
    Posts: 293

    Hi Phil,

    It is electrc start only.

    I disconnected all wiring up to the ignitor(electronic ignition) and coil(magneto).

    I used my business cards for the coil/flywheel gap on 1:eek:ld coil 2:new coil 3:modified briggs coil (I did this for grins knowin the fly magnet was wrong for bs magneto)

    Although I don't know if I am turnin 300rpm, the starter is new; the battery is strong and I could only wish my old truck would turn this fast. I am testing the ignition with the spark plug removed with no/extremely weak fire.

    Thank you Phil

    ------------I'm open to advise, thanks everyone--------------

  6. kawasaki1

    kawasaki1 LawnSite Member
    Posts: 108

    i've never had to replace a kawi flywheel because of bad magnets, yet. that doesn't mean they aren't bad though.

    the magnets on almost all flywheels are pretty tough, but look and see if there's hammer marks on them.

    the ignitor number seems correct, but i can't verify that until i go to work mon.

    did the coil you bought have a deere or kawi equivalent number? iirc the deere number is am109209 but i can't check that either until mon.

    since you posted the type and spec i can get the deere and kawi numbers mon. so you can compare.

    about the only thing to check before replacing the flywheel if all numbers are good is the white wire where it goes from the coil to the ignitor. maybe it's broken inside or grounded where it runs through the blower housing.

    eta.. are you using a spark checker or spark plug?
    some spark checkers do go bad (don't ask me how i know) and some plugs are bad out of the box.
  7. echoman8

    echoman8 LawnSite Senior Member
    Posts: 293

    In my shop we did at least 5,000 ignition repairs withou a single bad flywheel.

    There is magnetism on the fwheel.

    There are 2 screws attaching the mag to the fwheel. It appears that the magnet is glued also.

    I am sure the excitor is the correct number. A short test on the excitor is with a ohm meter. When the ohm polarity is reversed from the spade(connector) to the body, there is a different resistance indicating that it is not toasted.

    The coil. I got it from Tulsa Warehouse (Oklahoma). I found the kawa # on internet and googled. I assume that this coil was routed through Stens or other aftermarket.

    Hey, if you have time Monday --- great, But if your shop is like mine was, then Tue or Wed would be better.

    I ohm'd the wire from the ignitor to the coil. I had not thought of that, but, it is ok.

    My tests on the ignition.
    1: used spark tester; no visible fire
    2: used spark plug; grouned plug to engine block, no fire across gap
    3: bare spark plug wire to block; barely fire (if touching block)

    All tests will only show fire if spark plug wire is touching block. All connections are clean.

  8. echoman8

    echoman8 LawnSite Senior Member
    Posts: 293

    kawa deere #s fc420va22618 fou20vas10 lx172
  9. kawasaki1

    kawasaki1 LawnSite Member
    Posts: 108

    i can probably check them monday. it's gonna be hot again, and i can do it on break.:)

    it's gotta be something simple we're overlooking. i've run into a few jobs where i overlooked something simple only to discover it a couple of hours and a disassembled machine later.:rolleyes::dizzy:
  10. jkason

    jkason LawnSite Senior Member
    Posts: 548

    Replace the plug - might be bad internally. (Can't hurt)

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