lean cylinder 1977 KZ 1000

Discussion in 'Motorbike Technical Discussion' started by chris, May 5, 2006.

  1. chris

    chris Guest

    I picked up KZ for cheap (not running) first thing I did was clean the
    carbs, second put in a battery...it fired right up. I fouled the plugs
    right away so I replaced them and it ran ok, it was Idling high and
    loading at the stop lights. I pulled the carbs again and mechanically
    synched em, this helped alot. It idles very nice and the entire power
    band is strong, but through the whole process the # 3 plug comes out
    pure white and the others are tan to black but not too black. I have
    read a few posts about valve problems and I have the service manual,
    but I would like to narrow it down first. Any advice would help. Oh
    yeah I love the bike, I have wanted one for years, it's in very good
    shape the miles say 6700 looking at parts the bike it might be
    true..others not.

    1977 KZ 1000
    2004 Yam Kodiak
    chris, May 5, 2006
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  2. chris

    Ray Curry Guest

    I would check the fittings on that cylinder. The rubber boot or the
    vaccuum fitting on the boot could be cracked allowing air into that
    cylinder. Try spraying some WD40 on the boot in front of the carb while
    the bike is running and watch for signs in the exhaust that it's being
    sucked into the cylinder. I tended to remove the rubber covers over the
    fittings on the and tie them together with some vaccuum hose and small t
    fittings after syncing the carbs. It helps smooth idle and make off idle
    response smoother.
    Ray Curry, May 5, 2006
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  3. chris

    FB Guest

    The initial loading up and carboning of the plugs might have more to do
    with sticky floats, than with idle mixture adjustment.

    High fuel level in the float bowls makes it easier for the engine
    vacuum to suck
    up excessively rich idle mixture.

    Pump gasoline contains carburetor cleaning additives that will remove
    most of the gum and varnish deposited by evaporating gasoline. Or you
    can clean the carbs quicker using carburetor cleaners that contain
    xylene, acetone, and methyl alcohol.

    You can mix about 3 or 4 ounces of Berryman's B-12 Chemtool Choke and
    Carburetor Cleaner with a full tank of gasoline and ride the motorcycle
    slowly to get the cleaner to go through the idle circuits.

    B-12 is available in 15-ounce aerosol form or the 15-ounce liquid form.
    I buy both, they are about $3.00 a can from Wal*Mart.

    A plugged up idle circuit may be what is causing the # 3 spark plug to
    be pure white.

    Or, the intake valve might be set too tight on # 3 and that cylinder
    tends to push air backwards through the carburetor. You may have to
    remove the camshaft to re-shim the valves on that model, I don't

    The desireable color of spark plug insulators has changed since leaded
    gasoline phased out. Tuners aren't looking for tan or brown anymore.
    That was lead fouling anyway. Now experienced tuners are looking deep
    into the spark plug with a magnifying flashlight. They are looking for
    a narrow band of black soot down where the insulator meets the steel

    The KZ-1000 had old fashioned slide valve carbs, as I recall, and slide
    valve carbs have the idle mixture screw on the side of the carburetor
    body. If you want to lean out the idle mixture, turn the idle mixture
    screw counterclockwise to allow more air into the idle circuit.

    The idle jet on the # 3 carb might be plugged up. The aerosol B-12 is
    good for cleaning small jets once the carbs are removed, and you can
    also remove the idle mixture screw from that carb and spray aerosol
    B-12 down that hole to clean the passage out.
    FB, May 5, 2006
  4. chris

    SAMMM Guest

    does that one have constant velocity carbs on it/
    if so, check carefully for a leaky diaphragm in it.
    i had a similar problem with a different model and make.
    SAMMM, May 6, 2006
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