Kohler 28hp EFI problems

Discussion in 'Lawn Mowing' started by rookie03, Sep 22, 2009.

  1. rookie03

    rookie03 LawnSite Member
    from OK
    Messages: 184

    I have a Kohler 28hp EFI and I'm having problems with the mower. The engine has 2300 hours on it and it has started using oil. The biggest problem is that it is fouling spark plugs and getting to the point to where it will cut out and almost die. Does anyone have any idea on what could be the problem? What could be causing it to foul plugs? When I say foul plugs, I mean quick. I put brand new spark plugs in and within a day or so they are completely black. Clean them off and put them back in and it will run for a little while longer. Any ideas? Thanks for the help guys!
  2. milo

    milo LawnSite Bronze Member
    Messages: 1,303

    is it oil fouled? and gas fouled???
  3. Richard Martin

    Richard Martin LawnSite Fanatic
    Messages: 14,699

    Depending on your answer to Milo's question....

    Oil fouling is a head gasket issue (my first thought with a Kohler twin).

    Gas fouling is probably a EFI issue. Have you pulled the codes?
  4. HighlandLC

    HighlandLC LawnSite Member
    from CT
    Messages: 192

    And how fast is it using oil? Does it blow out smoke, and if so on startup or not, and what color ?
  5. milo

    milo LawnSite Bronze Member
    Messages: 1,303

    we need more info, i have a 28efi kohler only issue is once and a while like right at start up i get a big white cloud of white smoke but runs perfect and only does it after used and after ran up the trailer and does it more when leaning to rear, im 95% sure its the valve seal it dont use oil though. (others chime into my issue too)
    a head gasket i dont thinkis my problem or yours cause you would not foul plugs that way.
    if your smoking all the time white or blue than runs ruffprobally rings shot or head shot.
    if your not smoking but fouling plugs check for codes like martin said and probally a spark problem.
    yours could be a head gasket if smokes all the time or runs very bad all the time but if running good for a point and then acts up and fouls plug my guess is a spark issue
  6. Richard Martin

    Richard Martin LawnSite Fanatic
    Messages: 14,699

    That was exact what my first 25 would do. Foul the left hand plug and that head gasket was replaced repeatedly. We eventually just replaced the whole cylinder head and that finally cured the oil burning and head gasket issue. I kept trying to run the engine at the Dixie Chopper recommended 3750 RPM and it kept blowing head gaskets. When we'd pull the head off you could see where the gasket was burned through. On the 28 EFI that I have now every time i try to run it up to 3750 RPM it starts using oil. I'm leaving it down at 3600-3650 RPM no load.
  7. milo

    milo LawnSite Bronze Member
    Messages: 1,303

    really? u fouled the plug with the bad head gasket???? im perty sure my start smoking issue is 1 or both intake valve seals. dont a bad head gasket on these things smoke all the time when running? i know not much but enough to see or smell???
  8. puppypaws

    puppypaws LawnSite Fanatic
    Messages: 9,139

    2300 hrs is a goodly number of hrs on an air cooled engine even with hearing of 3 and 4 thousand hrs on a select few. The valve seals are probably shot and you should see the engine smoking, this will oil foul a plug very quickly if leaking bad enough. It is time for it to come apart to fine the culprit.
  9. topsites

    topsites LawnSite Fanatic
    Messages: 21,653

    Yup, either a complete rebuild or just replace it,
    that's just too many hours that, if the simple fixes
    don't do it, probably about that time anyhow.

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