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Weak Cylinder on 20hp Kohler

Discussion in 'Mechanic and Repair' started by Turfer, Aug 11, 2001.

  1. Turfer

    Turfer LawnSite Member
    Messages: 99

    I've developed a weak cylinder on my Walker, 20hp kohler (750 hours). I'm burning about 1/2 quart of oil every 5-8 hours and fouling a plug about every 10 hours. I know I need to get it fixed but I just can't find the time. Am I causing further damage by just letting it go until I can get it to the shop ? I do make sure it has enough oil and it's easy to tell when the plug is fouled. I'm using 10w30 mobil synthetic. I wonder if I could help it out by using a slightly heavier oil. I did put a fouler plug in it but it did not respond well. Thanks.
  2. PARKER124

    PARKER124 LawnSite Member
    Messages: 5

  3. John DiMartino

    John DiMartino LawnSite Silver Member
    Messages: 2,555

    It sounds like a head gasket for sure.Mine did the same thing,check the gas,fill the oil when is blown.
  4. captdevo

    captdevo LawnSite Senior Member
    Messages: 932

    is it smoking bad?

    Pull the head and check the gasket, head and block surface, and cylinder walls, if they are scratched or scarred, you're gonna need a rebuild.

    The key is to determine what caused this.

    Has it overheated?
    How long has it been using oil?
    Has it misfired?
    Ever have water in your fuel?

    When you remove the head make sure the block and the head are decked (go over them with a heavy file)

    You could keep running it, but you may cause more damage to your engine.

    regardless of the oil you use, you have a serious problem that needs attention.

    Good luck!!
  5. John DiMartino

    John DiMartino LawnSite Silver Member
    Messages: 2,555

    Running with blown head gaskets is very bad for the engine,the powerstroke pressure+compression pressure all go right into the crankcase thru the pushrod passage,where every head gasket blows.This pressure froths the oil,and forces excess amounts of crankcase pessure,more than the system was designed for,so the whole engie actually becomes pressurized,making seal leaks,and gasket leaks/blowouts much more likely.It would be much better if it blew out externally,between the exposed cooling fins no pressurizing crankcase,and you would know it blew right away.
  6. EJK2352

    EJK2352 LawnSite Bronze Member
    Messages: 1,150

    Check for blown head gasket for sure. John D. is right on the money. This is a very common problem w/ Kohler Command V-twin engines.:) ;) :) ED
  7. Turfer

    Turfer LawnSite Member
    Messages: 99

    Thanks for all your help guys. It's going under the knife next Monday. When this first started, I had just sold my backup walkbehind and was only left with a 21" for backup. Now I've got my GD chariot so I'm not in such a pinch anymore. I'll only have to 21" 4 - 5 lawns if the Walker isn't fixed by week's end. The problem is very deceptive because it runs so good with a new plug. It does smoke a little but not allot. Anyway, it will be ready for fall cleanups in a couple of weeks. Thanks.
  8. LES

    LES LawnSite Member
    Messages: 13

    I've worked on 8 walkers in the last two months and don't be suprised if it's more than a simple head gasket. 6 out of 8 needed short-blocks that came in with the same problems. Very common with walkers! No love for them in our shop!!!
  9. captdevo

    captdevo LawnSite Senior Member
    Messages: 932



    Walker doesn't make Kohler engines.

    Sounds Like a Kohler problem!
  10. Turfer

    Turfer LawnSite Member
    Messages: 99

    I got the call from the dealer today about my Walker. New engine needed ! It's been an expensive month. He said there was too much damage for a rebuild. He really wasn't sure what caused it but said there was allot of debris in the engine. He did mention there was a metal cover missing from the air cleaner which I wasn't aware of. I have cleaned the carburetor a few times and noticed how easy it got dirty and it was very sensitive to wet weather. This cover may have been missing for a while and it just took it's toll. He said a short block would not be advisable because of the amount of bore he would have to take out because of the huge gap between the cylinder and piston and the cylinder wall damage. In hind sight, I probably could have saved this engine if I had taken it in earlier. I just kept the oil filled and kept the plugs clean and ran it for a couple of months and let it smoke. Expensive lesson learned !!! (800 hours)

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