1. Missed the live Ask the Expert event?
    Catch up on the conversation about fertilization strategies for success with the experts at Koch Turf & Ornamental in the Fertilizer Application forum.

    Dismiss Notice

Kohler 25 HP Misfiring

Discussion in 'Mechanic and Repair' started by mvgerb, Jun 3, 2003.

  1. mvgerb

    mvgerb LawnSite Member
    Messages: 6

    My Gravely 260Z with Kohler 25 HP is missfiring at full throttle.
    Backfiring through the airbox. Checked carborator, plugs, air filter, and fuel filter however problem continues.
    Also had both head rebuilt, and problem began shortly thereafter!
    Runs well at half throttle. Any info would be appreciated
  2. General Grounds

    General Grounds LawnSite Senior Member
    Messages: 902

    :blob3: govenor spring, perhaps bad head gasket????
  3. bob

    bob LawnSite Platinum Member
    from DE
    Messages: 4,260

    It sounds like it might be the coil. Those are the same symptoms my Kawasaki had when the coil went.
  4. Bruce

    Bruce LawnSite Member
    from MN
    Messages: 45

    I had the same motor. I had the Intake Gasket go out twice on me. Sounds like what mine was doing.Cost me $500.00 to get it fix.First time it was under warrenty.
  5. taylob

    taylob LawnSite Member
    from Texas
    Messages: 14

    Mvgerb, you might want to try checking out to see if it is shorting to ground on the kill wire, it is located on the engine side wire harness and is white, disconnect it from the harness and this will isolate the engine from all safety switches. then try running the engine. If it still misses you know it is in the engine, next check the connections on the coils themselves to see if the wires are loose. there are two wires to each coils a yellow and brown, make sure they are very tight, if not the engine will miss because the signal to the spark advance module is interrupted. If all that is good then you will need a spark tester that Kohler reccommends part #KO1046, which can be purchased from SPX tools, 800-533-0492. This tester was built for this type of ignition system to provide enough resistance on the ignition to make it fire if you use a typical tester like an inline tester or other there is no resistance and it may fire giving you false test. Also you could get service bulletin 253 from a local dealer and it will walk you through the test procedures. Good luck

Share This Page