Another Kawasaki Engine Surging Thread

Discussion in 'Mechanic and Repair' started by RocketLab, Aug 11, 2011.

  1. RocketLab

    RocketLab LawnSite Member
    Messages: 83

    Hi Everyone,
    have done extensive searching on this subject and have a few questions.

    I have a Kawasaki FH480V CS-20 that started surging as we started it to begin work on the 4th yard that day. Ran perfect til then. We did fill up that morning with new fuel. Engine has 731 hours on it. Never had a valve adjustment. Engine seems to surge at all speeds beginning maybe 3-5 seconds after starting. Choke doesn't seem to alter the surging much.

    Have replaced the fuel filter and attempted to clean the carb with cleaner and compressed air. .

    replaced the manifold o rings in case there was any leakage. No visible damage to the manifold or old o rings but a small bit of grunge seemed to have seeped past one of them.

    removed and cleaned the pilot jet

    removed and cleaned the main jet

    Question is how do you get the nozzle out to clean it as well?

    Any other suggestions or steps would be appreciated as well.
  2. piston slapper

    piston slapper LawnSite Platinum Member
    Messages: 4,289

    The emulsion tube will either be slotted for a flat blade screwdriver, or be held in by the jet .If its held in by the jet, you may have to push down on it from the top to get it to move.
  3. RocketLab

    RocketLab LawnSite Member
    Messages: 83

    Thanks, piston slapper. So looking at the top of the carb body there is the smaller hole with the small orfice. Is this the top of the emulsion tube? If so how hard can you push on this say with a small punch without damaging something? I've already tried nothing more than hand pressure with no movement. Can you tap with a hammer?
  4. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    If the emulsion tube doesn't come out easily just leave it in place, The holes in it are pretty large and I've never seen them get plugged on a recently running engine. Just shoot some carb cleaner through it followed with air and you should be good to go.

    Just for info, The emulsion tube sticks up inside the throat of the carb between the throttle and choke butterflies, This is where you would push it down and out.

    If applying the choke made little difference in the surge you may want to check/adjust the governor if the carb cleaning has no effect.....

  5. RocketLab

    RocketLab LawnSite Member
    Messages: 83

    Restrorob I put the carb back on to check choke effect. When applying choke it initially increases the surging then smooths out some before almost stalling the engine. To get a somewhat smooth idle you have to constantly move the choke.

    i have bought a gallon can of carb cleaner to soak the carb. Do I need to take off the foam surrounding the choke shaft end and the plastic arm before soaking? Also how much play in thet choke shaft is too much? I would say it's got a 1/16the of an inch of play. And how do you take off the choke shaft if necessary? Do you remove the butterfly somehow and slide it out.

    Again thanks for the help I really need to get this mower back to work.
  6. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    Today's carb soak cleaners are more forgiving on plastic parts than they were some 15-20 yrs. ago but will still affect the foam seal, If you have play in the choke shaft it really should be replaced. Kawi's list price is $10 and change, The play won't effect the issue your having but let sand/dust get sucked into carb throat into the engine.

    If you look at the bottom of the butterfly you will see four tabs stamped in it, These tabs hold it in the slot of the shaft.

    I use the smallest blade in my pocket knife and CAREFULLY slide the tip between the two tabs and shaft on the bottom, This spreads the slot open. I then use my small channel lock pliers and grab each side of the butterfly (one jaw on top the other on my knife blade) and slide it out of the slot, Then the shaft and foam seal can be removed.

    Have you removed the limit cap on the low speed adjuster yet ?
  7. RocketLab

    RocketLab LawnSite Member
    Messages: 83

    Yes on the limit cap.
  8. RocketLab

    RocketLab LawnSite Member
    Messages: 83

    Well soaked the carb for 24 hours, blew every passage out put it all back together and no improvement. Have not changed the fuel pump or messed with the governor yet but I'm out of ideas at this point. :dizzy:

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