Kawasaki: Detailed Carb Problem

Discussion in 'Mechanic and Repair' started by johnnyk, May 26, 2010.

  1. johnnyk

    johnnyk LawnSite Member
    from nj
    Messages: 11

    Engine: Kaw, 19HP, FH601V-BS23-R
    Eng No: FH601VBS7946
    Carb: Nikki 621266
    I am having difficulty starting this engine; it will start ONLY when cold.
    When it starts it runs well at all rpm's and with/without the deck engaged.
    I can run it for as long as I want without any problems, but when I turn it off it will not restart.
    Parts replaced, electrical: both ignition coils, voltage regulator, plugs.
    Parts replaced, carb: o-rings (pn 11061, 92055, 92055B, 11061A), float valve (pn 16030), gasket 11061B.
    Fuel pump and filter also replaced.
    Having replaced these parts, based on a previous thread where it appeared that the o-rings had swelled over time I thought I had the problem licked. WRONG! The new o-rings looked like the old ones.
    Battery checks out at 13.2 idle, 14.0 running. Non-regulated voltage at mid throttle is 23v, high idle is 31volts.
    Valves adjusted to .004-.005 at TDC compression. ACR seems to be working fine as the exhaust valve opens and closes a few degrees before TDC.
    Pulled flywheel to check for a possible sheared woodruff key; key was intact.
    Replaced it anyway and cleaned the internal magnets and all magnets appear to have a good pull.
    Stator coil was checked with resistance measured at about 0.1 ohm.

    My question is this: I did not replace the float or it's corresponding spacer as they both looked fine upon close inspection. But, having it apart again I can look into the spacer (pn 92026) and clearly see that the jets ( #104 and 108) are clean with no visible problems. But, when I look into the cavities that are molded into the spacer for the idle jets I see nothing. I don't see how any gas can get into the idle ports as there appears to be no opening in the spacer. How does the gas get into the idle ports? There are some flashing marks from the mold at the bottom of these cavities (about .75 to 1.0 inches long), but they are clearly not openings. Anybody know how gas gets into the idle ports? (Both idle mixture plugs were removed and the mixture screws examined. The right port had a damaged taper so I replaced this screw. Both screws were adjusted to 2.25 turns out on the left, and 1.25 turns out on the right. These were about the same as the original screws were adjusted.)

    Anybody have any specific input?
    Thanks allot for your input.
  2. bigdodge150

    bigdodge150 LawnSite Member
    Messages: 43

    are you on low idle when you shut it down?
    Posted via Mobile Device
  3. johnnyk

    johnnyk LawnSite Member
    from nj
    Messages: 11

    Yes, I always go to low idle for about a minute, then I shut down.
    Forgot to mention that the mower has about 226 hours on it and it had been very reliable up to this point.
  4. bigdodge150

    bigdodge150 LawnSite Member
    Messages: 43

    sounds like you've done it all is the gas tank pressurizing from the heat and pushin fuel trough the carb ?( bad gas cap?) that's about all I can think of
    Posted via Mobile Device
  5. johnnyk

    johnnyk LawnSite Member
    from nj
    Messages: 11

    I took both caps off and checked the vents and they are free and clear. Fuel flows freely from both tanks. When I took the carb off yesterday I made a point to not empty the bowl so I could see if the bowl was full and the float was working properly. The fuel level with the float still in the bowl was good, about .125" below the top.
  6. johnnyk

    johnnyk LawnSite Member
    from nj
    Messages: 11

    Update: I must be missing something related to the carb, so if anyone has any ideas please post.
  7. VT_Grassman

    VT_Grassman LawnSite Member
    from Vermont
    Messages: 56

    Since you said compression is OK, it HAS to be either fuel or ignition.

    a) Have you checked for spark when it won't start?
    b) Look at a spark plug when this happens and describe its condition.
    c) It is either not getting fuel to restart or getting too much. Do you smell gas when this happens?

    I feel badly that you spent money you probably didn't have to. It is sometimes easier to troubleshoot before buying allot of parts - which may create more problems since you introduce more "variables" into things.:dizzy:

    Hope this gives you some direction and helps to solve it!

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