Kohler 26hp efi ?

Discussion in 'Mechanic and Repair' started by JJ Lawn, Aug 11, 2005.

  1. JJ Lawn

    JJ Lawn LawnSite Senior Member
    Posts: 350

    At 1200 hours, one of the rocker arm bolts backed out, and the rocker arm came off causing some damage to the push rod. Replaced rod and am back in business.

    But should this have happened?? I called Kohler, and was told No, but there is nothing that could be done about this but to periodically check torque on rocker arm bolts. Funny, I don't remember reading about this in the service manual.

    A friend of mine with the same engine, had the same thing happen to his. I heard the other day that there is another Walker in the shop with the same problem. I called the dealer, and they are also baffled by this. So far there is no word from Walker, or Kohler as to why this is happening.

    Has anyone else suffered this problem with this engine? If so, what was the outcome?

  2. mikemerritt

    mikemerritt LawnSite Member
    from MS
    Posts: 42

    I've seen it twice in 3 years. Both times resulted in bent rods and both were back in the grass once put back together.

    I have no answer to your question but Kohler has had a world of trouble with the lifter/valve train area on these engines.

  3. Jman

    Jman LawnSite Member
    Posts: 217

    What weight oil are you using?? I've heard of this problem when people use the incorrect weight of oil for temp conditions. The oil pump's pressure relief valve in the Kohler can not relieve enough thick cold oil to keep pressures down on cold start up. I've seen the oil pressure go above 90 psi. That causes the hydraulic valve lifter to over extend, which allows the valve spring to bottom out, then something has to give. A lot of people are recommending 15W-40 and 15W-50 oils in engines. I don't believe in that at all. If it is such good oil why are vehicle manufacturers now recommending 5W-20 in new V-8 engines?? Just my two cents worth.
  4. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    I am yet to see this problem, But when this accures the rocker stud should be removed completely and carb. choke cleaner sprayed in the hole and on the stud to clean all oil from the threads and lock-tite applied upon re-installing.
    Kohler recommends ONLY 10w-30 regular grade oil in ALL command engines and NO synthetic at all above 40 degrees.
  5. Redneckn

    Redneckn LawnSite Senior Member
    Posts: 294

    I've seen a few of these. Not enough for it to be considered a real "constant" problem. I have had my guys take out the stud, clean, threadlock and put back in.
  6. Jman

    Jman LawnSite Member
    Posts: 217

    Actually synthetic is ok at any temp as long as it meets the specs (10W-30) and classification. This is in the 2005 Kohler update notebook, page 32. It also states that the oil change should be at the Kohler recommended intervals and run the engine at least 50 hours on petroleum based oil to seat the rings in when new.
  7. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    Thanks for the correction Jman, It's a little difficult to remember everything they cram into these one day seminars.
    It seems they would have revised service bulletin 193 on the change also as they did back in 1-99, Guess their running behind.
  8. Brianslawn

    Brianslawn LawnSite Silver Member
    Posts: 2,004

    little off the topic but does anyone know what temp this engine should run at full throttle, parked with no blades spinning. computer is reading 275-290 derees F. wondered if that sounded hot
  9. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    Sorry, I havn't had a reason to shoot one with my temp gun yet and the only one in the shop right now is new and not serviced yet or I would check it out for you. I don't remember anything about engine running temps, So I checked the service manual and couldn't find anything either.
    So you got me on that one !
  10. Brianslawn

    Brianslawn LawnSite Silver Member
    Posts: 2,004

    #1 cylinder overheats. exhaust pipe glows bright orange in dark. just started doing it after i put ground upgrade kit on it to fix another problem. i tried brand new head assembly and still does it. were going to do leak down test to check for leaky head gasket. also going to try different muffler. although this muffler was new upgrade a year ago. O2 voltage starts fluctuating real high to real low. 0.8 then 0.2. jumps back and forth rapidly for few secs then stabilizes for a few secs. should be between 0.4 and 0.6, right. no trouble codes whats so ever. last time we mowed with it cyl head temp warning would go off after 10 min. 2002 walker mower around 1000 hrs.

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