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John Deere 425 - firing on one cylinder

walt72
13 years ago

I have a JD425 with 20hp water cooled Kawasaki engine. It's always run strong. It intermittently started loosing a lot of power (bogging down) when mowing. I ran thru it and discovered that there's no spark on the right cylinder.

I've replaced both spark plugs & right coil pack. Piston goes up & down when turning motor by hand, & running with OHV cover off I can see that the valves open & close while running... just no spark about 95% of the time on the right side. I'm stumped. Any ideas? Thanks!

Comments (18)

  • walt2002
    13 years ago

    Don't know about Kawas but B&S & Kohler V twins use a coil for each cylinder. IF your Kawa is a V twin, might look into that.

    Walt Conner

  • mownie
    13 years ago

    ***"no spark 95% of the time"***
    Do you literally mean "no spark"? or are you saying "the cylinder is dead 95% of the time"?
    You replaced the "coil pack" for the right bank. Does the Kaw coil have a molded spark plug cable or do you have to transfer your old spark plug cable to the new coil?
    I only have the Kawasaki service manual for their FD671D thru FD791D engines, I don't know whether the JD proprietary engine is different, or not.
    The wiring schematic shows the ignition system to be a very basic "magneto type, flywheel powered, grounding wire kill" configuration. Both "kill wires" converge into a single circuit without any diodes. Therefore, if either of the kill wires were chafed and shorting to ground, it would affect both coils and not just the right bank.
    So, it kinda boils down to this, are you absolutely certain that you are in fact not getting spark when the cylinder is dead? Unless the old spark plug cable had to be transferred to the new coil, I don't see anything else that could kill the spark to the right bank without also killing the spark to the right bank.

  • KLW1
    11 years ago

    Did you ever figure this out? I have a 93 425 doing the exact same thing. I replaced the coil and plug wire. Still no spark on right side only.

  • bill_kapaun
    11 years ago

    As mownie stated-
    Are you sure it's no spark or just no run.
    Verify with a spark plug tester.

    Some twin engines have a 2 barrel carb, and if one jet is clogged, it only runs on one cylinder.

  • tomplum
    11 years ago

    Good words to verify the loss of spark. Really, these can be messy or actually really simple. If you have not already installed a new set of spark plugs, now is the time to do so. Save the old plugs --carefully comparing the deposits between the two. Does it run the same warm vs cold? BTw, your particular engine should be a 1 bbl carb

  • aws425
    11 years ago

    Replace time delay module. About $20 from your dealer.

  • bjlewis101
    10 years ago

    I have the same problem as the original post and have troubleshooted. Was the problem corrected? If so how? Was it the time delay module or something else?

  • tomplum
    10 years ago

    Nice tip.I use ECUs for the X series off Ebay which are identical to the dealers. Edit: Bummer, I thought to myself I have just one of these left after reading this thread. I see what once was 25$ shipped to my door is now over double that. :/

    This post was edited by tomplum on Sun, Nov 10, 13 at 11:39

  • jerryhuddleston65
    8 years ago

    On late model Kaw engines u have to replace both coils at least it's wise and they are marked #1 and #2


  • macsrgr8
    7 years ago

    Hope someone still around with answers to this question. Have absolutely no spark to left cylinder. Replaced plugs, both coils, ignitor, and coil relay. This is 2001 425 2 wheel steering. Also took carb off cleaned and put back on. Only has 572 hours, been garaged since new. Use it strictly for tilling and other implements. Have 1993 with 60" deck for mowing 3 acres. It has 2400 hours and still runs well and has good power. Any ideas? Thanks

  • Bobby Parnell
    6 years ago

    I got same prob did.you or anyone here have solution

  • Timothy Sean
    5 years ago
    last modified: 5 years ago

    OK...I just chased this down on my Argo with the same/similar engine. I had spark on a single cylinder. So I assumed the igniter or a coil. Swapped coils and the suspect coil worked after swapping...so igniter? NOPE. I was just about to buy a $200 igniter (ignition box) and wigged the connectors and it kicked up my RPM. The spade connectors corrode. I pulled each one, cleaned and flowed a little solder on them and it runs like new again. Yes...my issue was corroded connectors. My connectors all had crimps that looked perfectly fine...but had intermittent bad connections after 18 years. You could also cut the connector and solder and shrink wrap it you aren't good with a pick and small connectors. I had pulled my igniter circuit board out and it looked brand new. Wiggle and twist those connectors with engine running...if your RMP jumps up...you have the same problem I did.

  • ssewalk1
    5 years ago

    Good advice Tim , spade connectors are infamous for this problem . Much safer to hard wire or solder / shrink wrap as you have advised !



  • HU-40171493
    5 years ago

    I have a 1998 John Deere 425 that's having the same problem and I've changed the left side coil and cut both plastic plugs off and hard wired them and changed the timing delay, twice and still doing it, sometime it starts right up and runs for a while, and then the cylinder stops firing, why ??

  • HU-913159304
    5 years ago

    Yes I had the same problem its the igniter part No AM105574 that you need to get it right OK.

  • Tommy Minton
    4 years ago
    last modified: 4 years ago

    Have same problem

  • ssewalk1
    4 years ago

    Same fix,s !

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