2001 Dixie Valve Clatter on 25 HP

Discussion in 'Lawn Mowing' started by luckylawnboy, May 4, 2001.

  1. luckylawnboy

    luckylawnboy LawnSite Senior Member
    Posts: 431

    I have been hearing what I think is my valves clattering really loud. My 2001 Flatlander 60" with the 25 hp Kohler has seem to be a funny engine. It only has 120 hours on it When I shut the machine off it wants to diesel and back fire really bad. Now the valves clatter when you start it, and some time the entire time that I am mowing. The dealer said that this was all normal , but the thing just sound like a piece of poop. plus the cut has started to leave little strips of grass un cut right under the shoot side blade. I started out loving this thing, now it seems to be having some problems. If any one has had any experience E-mail me or respond
  2. Richard Martin

    Richard Martin LawnSite Fanatic
    Posts: 14,700

    Before you go getting upset with Dixie Chopper none of your problems has anything to do with the mower itself.

    About the valves, you didn't say what weight oil you are using in it. Kohler lifters are sensitive and during the hot months a straight 30 weight is required. Please advise us on what weight of oil you are using.

    About the deiseling, are you letting the mower run for a minute or two before you shut it off? These engines require a short "cool off" period.

    The valve chatter while running goes back to the oil again. Do an oil and filter (not the Amsoil bypass filter) change and use a good quality oil.

    To cure the windrowing effect the center and/or the right hand blade is worn out. Replace them. 100 to 125 hours is the life expectancy of blades in my area.

  3. awm

    awm LawnSite Gold Member
    Posts: 3,354

    try a tank of mid grade gas. it may quiet things dn a bit.
    if you do this ,give result as a lotof us running kohler . good luck
  4. Eric ELM

    Eric ELM Husband, Father, Friend, Angel
    Posts: 4,831

    From what I have heard, you should never run straight 30 oil in a Kohler with hydraulic valves. The only time I've had problems with lifter noise is if it is a fuz over filled with oil. It seems like the crank hits the oil and causes the oil to foam and then you get lifter noise. Check to see if you are over filled a bit. If so drain out a bit of it.

    When it gets hot out, I run 15/40 Shell Rotella T and I have not had any lifter noise at all. Richard is right, you have to let the Kohlers run for a minute or so after idling down to cool off a bit or they will "diesel" or run backwards.

    The uncut grass sounds like a build up of grass under the deck or bad blades.
  5. luckylawnboy

    luckylawnboy LawnSite Senior Member
    Posts: 431

    My oil is 10W30. They told me that Kohler said to use this oil at all times now. The older Kohlers used straigh 30 but now we are supposed to use 10W30. The blade were new but getting dull. They were aftermarket but looked the same. Putting the orginals lazor sharp today, will let you know my results. Is 3700 RPM too much that what it came back from the dealer as?? I have a bunch of pictures on my digital camera but need some direction as to how to post.

  6. Eric ELM

    Eric ELM Husband, Father, Friend, Angel
    Posts: 4,831

    You are correct, the older Kohlers (Magnum engines) did use straight 30 weight oil and they did not have hydraulic lifters.

    To post pictures, check out my page on this on my website. Go to my LINKS page, COMPUTER, and then click Posting Pictures. It tells how to do this. If you still have problems, email me.
  7. Jman

    Jman LawnSite Member
    Posts: 217

    To avoid dieseling on the Kohler shut the engine off at wide open throttle. Don't idle it down to cool off, you take most of the air away and this is an air cooled engine. It has a shut-off valve in the carb that shuts off fuel in the high speed jet only, it does not shut off fuel flow in the idle circuit. This will stop all of the dieseling problems. Also make sure you use a heavy duty 10W-30 oil, something that has a S and C rating. This will help the lifter noise and also like Eric said do not overfill the oil at all.
  8. cst51

    cst51 LawnSite Member
    Posts: 72

    My 23 kohler is doing the same thing when I first start it up for the day!! After about 5-10 minutes it goes away!! I think eric is right. I topped off the oil at the beginning of the week and I may have put too much oil in it causing it to knock horribly. I would get a new set of blades or just sharpen the ones more frequently that you are using now!!
    Good Luck
  9. luckylawnboy

    luckylawnboy LawnSite Senior Member
    Posts: 431

    So Who do I beleive. Shut off at WOT or Idle it down?? Put the original blades at it seem to be working fine. What pitch should the deck be at. Some how it mysterly sp got 1/2 lower on the shoot side, so in stead of raising it back to level I lower the closed side down and I think I messed the pitch up. I may look on Eric's site and see what he has to say. Well luch is over back to work

  10. ChadsLawn

    ChadsLawn LawnSite Bronze Member
    Posts: 1,110

    Jman is right 110%.If i shut my Kohler 22hp off at idle it wants to stay running.but if i shut it down at 3/4 or higher its fine.as far as valve clattering never had a problem.I use 10w/30 synthetic always have.

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