Puzzled by 28 HP Kawasaki problem

Discussion in 'Mechanic and Repair' started by arkie_3_fan, Nov 30, 2012.

  1. arkie_3_fan

    arkie_3_fan LawnSite Member
    Posts: 77

    The 28 HP Kawasaki motor on my Exmark has been having issues for several months now and they seem to be getting worse.
    I took it too my dealer and they of course blamed it on ethanol in the gas and all of that sort of thing. Even though it's only had maybe 3 or 4 gallons of gas with ethanol ran in it and that was 2 years ago.
    I'm not sure what they did to it, but it ran a little bitter for about 4 hours worth of mowing and now it's sputtering and missing worse than before.
    It almost seems as if the motor is starving for fuel or something. I've done the obvious stuff such as new plugs and fuel filter but that hasn't seemed to help.
    What I have noticed is that when I turn the fuel petcock (fuel filter is located between there and the motor if that matters) to the off position while the mower is running, the motor smooths out and runs fine till it runs out of gas. The second I turn the petcock back to on, the motor goes to cutting up and sputtering, missing, etc...
    Any suggestions on what the problem could be?
     
  2. piston slapper

    piston slapper LawnSite Platinum Member
    Posts: 4,240

    Your carb is running rich...flooding or partially choked...
     
  3. piston slapper

    piston slapper LawnSite Platinum Member
    Posts: 4,240

    You may want to make sure the gas caps are venting...loosen the caps and see if it clears..
     
  4. arkie_3_fan

    arkie_3_fan LawnSite Member
    Posts: 77

    Thanks for the suggestion. I'll give that a try sometime this weekend. I'll also take a look at the choke and make sure that's it's not still on slightly when the lever is in the off position.
     
  5. arkie_3_fan

    arkie_3_fan LawnSite Member
    Posts: 77

    Well, I tried loosening the gas caps and that didn't help any. From what I can tell, the choke looks to be fully disengaging as well.
    Guess it's back to the drawing board.
     
  6. piston slapper

    piston slapper LawnSite Platinum Member
    Posts: 4,240

    I've seen a few of those fuelvalves go bad..there should be a good amount of fuel in the line going to the fuelpump...
    To get an immediate response when turning that valve is somewhat suspect....
     
  7. arkie_3_fan

    arkie_3_fan LawnSite Member
    Posts: 77

    So what should my next step be? Replace the shut-off valve?
     
  8. hackitdown

    hackitdown LawnSite Silver Member
    Posts: 2,487

    The shut-off valves are pretty inexpensive, it may be worth trying. Can you swap with another machine? Maybe it is a fuel line, or a clamp or connection to the valve. I had a leaky fuel line inside the fuel tank on a Gravely recently, and it wouldn't pull gas up. Very cheap repair.

    Does it have 2 fuel tanks? Does it happen on both fuel tanks? If so it is probably "after" the petcock.
     
  9. piston slapper

    piston slapper LawnSite Platinum Member
    Posts: 4,240

    I've got a lazer that you have to get the valve in the right place or the fuel won't flow..
    The plate that swings up over the deck pulleys hits against the valve when you lift it...
     
  10. BigFish

    BigFish LawnSite Silver Member
    Posts: 2,919

    If I'm not mistaken, they got a check valve in each line to prevent backflow.
    I would see if they are sticking or clogged.
     

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