Kawasaki Loss of Power

Discussion in 'Homeowner Assistance Forum' started by iceberger, Jul 5, 2009.

  1. iceberger

    iceberger LawnSite Member
    Messages: 23

    I'm a homeowner with a Husqvarna IZ4821 zero turn mower with a 21 HP Kawasaki FH641V V-Twin engine. When I start it (it starts great) and drive without the blade engaged is does OK for power (not great, but OK), but when I engage the blade it REALLY bogs down and almost stalls. I have to go very slowly. The mower only has about 200 hours on it, and I've changed the oil and filter at least once a year. The air filter is good. The plugs don't appear to be fouled and the fuel filter is OK.

    I've had it in the shop for a "stuck float" that somehow let oil into the gas, and it hasn't run right since, power wise. He told me to put Seafoam in the gas to keep it from happening again. It doesn't burn oil or smoke when I run it.

    I've looking for suggestions as to what might be wrong, and what I can do to fix it.
  2. Joeypole

    Joeypole LawnSite Member
    Messages: 46

    Sounds to me like a Carb problem. The stuck float was probably caused by leaving fuel in it too long. This caused it to "gum" up and stick the float.

    Definately sounds like a fueling problem. With the new Ethanol fuel it eats gaskets and causes "gumming" much easier than the older gas.

    When the mower is calling for more power for when the mower is engaged you aren't getting the fuel. Could be your fuel pump (if its a vacuum operated pump) could be "gummed" up as well.

    I would take the carb off and drop the bowl and clean it with carb cleaner and hit the float needle. You should probably get the bowl gasket and a couple other gaskets just in case. If it was a small older pusher I would just drop the bowl clean it and slap it together, but something like what you have with only 200 hours I would do it right.

    You may be able to get a carb rebuild kit with new needles and gaskets for cheap.

    I would syphon the gas out of it first. Check the bottom of the tank for residue, clean it if possible. Then change the fuel filter and put new gas in and see what happens. If that doesn't work then look at the above steps with the carb. If you are mechanically inclined the carbs are not that bad to work on, just make sure you have a clean surface when taking it apart and such. Even the smallest outside particle will effect your carb.

    The Seafoam may clean it out as well but not right away.

    I'd venture to guess its due to bad fuel and "gumming", but I'm a newbie!!!
  3. Joeypole

    Joeypole LawnSite Member
    Messages: 46

    One more thing it could be is the carb could be out of adjustment.

    If the person who fixed the stuck float played with the carb adjustment than that could explain it as well.

    I don't know what adjustments are on your carb but it could be one of the screw adjustments. Had that issue with my snowblower losing power after I rebuilt the carb.
  4. LarryF

    LarryF LawnSite Bronze Member
    Messages: 1,181

    Kawasaki engines have a bad reputation with their coils. An easy, no-cost test you can do is to pull the plug lead and check the resistance between it an ground. Should be about 6000 ohms. Just a suggestion, but that's what you asked for. If that's it, changing a coil is pretty easy.
  5. iceberger

    iceberger LawnSite Member
    Messages: 23

    Thanks for the tip on the coil. Yesterday I noticed that the exhaust was blowing on the ground in addition to coming out the muffler. I put my hand near the gasket on the exhaust manifold and felt a lot of exhaust. Could that be causing the engine to lose compression?

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