Lawn mower repair question.

Discussion in 'Home Repair' started by digitkgb@yahoo.com, Aug 19, 2006.

  1. Guest

    Hi.
    Yesterday while I was mowing the lawn, my mower engine suddenly
    stopped. The blade continued to spin until it slowed to a stop. It did
    not strike any objects. It was working fine up to this point.

    When I attempt to start the mower by pulling the string, the blade will
    spin quietly, but I do not hear the engine try to engage. Additionally,
    it feels "loose" when I pull the string; previously, I could hear the
    engine cranking, but not anymore.

    I'm not very experienced with lawn mower or small engine repair, but I
    did some basic troubleshooting by looking at guides on the web. The
    flywheel key, and the blade adaptor key both seem to be intact. The gas
    is fresh. Oil was recently filled.

    My mower is a Craftsman, model 143.996504 with a 6.5 Eager-1 (Tecumseh)
    4-cycle engine (917.377431).

    Any ideas?

    Thanks.
    , Aug 19, 2006
    #1
  2. Guest

    remove plug, ground ignition wire well to engine block away from plug
    area.

    put finger gently over plug, pull or get someone to pull cord.

    do you feel compression? in and out feeling

    sounds like broken valve etc from your description easy to pull.......
    , Aug 19, 2006
    #2
  3. Engines basically don't run for one of two reasons:

    1. Fuel
    2. Spark

    If you pull off the spark plug wire, and hold it near the engine (mayb
    1/4"), do you get a spark while cranking the engine?

    Remove the spark plug (special wrench/socket needed), is the gap either
    excessive ( > 0.030"), or bridged with carbon fouling? If either,
    clean, reset gap, and put the plug back in.

    If you are getting fuel, you should be able to smell it. The plug
    should be wet, if there is no spark.

    How about the air filter? If it is the sponge type, it needs to be
    washed out now and then. If it is the paper kind, they have to be
    replaced every season or so. Take a good look at it. In a pinch, use a
    whisk broom to clean off the grass clippings, crud, on the surface of
    the air filter. Put it back in.

    That should give you a good start. Also, the manual that comes with
    your mower should give basic maintainence tasks that you can do.

    When you turn the engine over with the pull cord, you should feel some
    compression, unless the engine is very worn.
    professorpaul, Aug 19, 2006
    #3
  4. DanG Guest

    If you pull the cord but don't feel and/or hear the resistance of
    compression, it is probably trash. You've lost a valve or ring.
    I would guess that you would not be comfortable taking the motor
    apart to see what may be holding a valve open.

    Feeling for compression at the spark plug hole with the spark plug
    out is more scientific.

    My personal decisions about small engines:
    No compression - trash can
    Bent crank - trash can
    Otherwise they are usually fixable.
    If you have compression, it is probably the flywheel key. You
    cannot tell unless you remove the flywheel which requires removing
    the pull rope mechanism, the shroud, and probably the fuel tank.
    This give you the opportunity to reset the magneto, slip in a new
    flywheel key (under $5), and clean out the old dead grass and
    crud. It would be a great time to give it a fresh pull rope too,
    before the existing one breaks.
    ______________________________
    Keep the whole world singing . . . .
    DanG (remove the sevens)




    <> wrote in message
    news:...
    > Hi.
    > Yesterday while I was mowing the lawn, my mower engine suddenly
    > stopped. The blade continued to spin until it slowed to a stop.
    > It did
    > not strike any objects. It was working fine up to this point.
    >
    > When I attempt to start the mower by pulling the string, the
    > blade will
    > spin quietly, but I do not hear the engine try to engage.
    > Additionally,
    > it feels "loose" when I pull the string; previously, I could
    > hear the
    > engine cranking, but not anymore.
    >
    > I'm not very experienced with lawn mower or small engine repair,
    > but I
    > did some basic troubleshooting by looking at guides on the web.
    > The
    > flywheel key, and the blade adaptor key both seem to be intact.
    > The gas
    > is fresh. Oil was recently filled.
    >
    > My mower is a Craftsman, model 143.996504 with a 6.5 Eager-1
    > (Tecumseh)
    > 4-cycle engine (917.377431).
    >
    > Any ideas?
    >
    > Thanks.
    >
    DanG, Aug 19, 2006
    #4
  5. Rich256 Guest

    wrote:
    > Hi.
    > Yesterday while I was mowing the lawn, my mower engine suddenly
    > stopped. The blade continued to spin until it slowed to a stop. It did
    > not strike any objects. It was working fine up to this point.
    >
    > When I attempt to start the mower by pulling the string, the blade will
    > spin quietly, but I do not hear the engine try to engage. Additionally,
    > it feels "loose" when I pull the string; previously, I could hear the
    > engine cranking, but not anymore.
    >
    > I'm not very experienced with lawn mower or small engine repair, but I
    > did some basic troubleshooting by looking at guides on the web. The
    > flywheel key, and the blade adaptor key both seem to be intact. The gas
    > is fresh. Oil was recently filled.
    >
    > My mower is a Craftsman, model 143.996504 with a 6.5 Eager-1 (Tecumseh)
    > 4-cycle engine (917.377431).
    >
    > Any ideas?
    >
    > Thanks.
    >


    I will go with the lost compression. If you are up to it you could pull
    off the head and see if a valve is broke. I do remember one one rare
    occasion a valve stuck open. Just took some lubricant to get it moving
    again.
    Rich256, Aug 19, 2006
    #5
  6. Pull the spark plug wire off, and secure it well away from the spark
    plug.

    Leave the plug in.

    Tip the mower on its side, and try to turn the blade backwards of the
    usual direction.

    If it spins freely, scrap the mower, and get another one. If it binds
    and gets hard to turn at one or two places in the revolution, then you
    have compression. Proceed to look for other problems.

    --

    Christopher A. Young
    You can't shout down a troll.
    You have to starve them.
    ..

    <> wrote in message
    news:...
    Hi.
    Yesterday while I was mowing the lawn, my mower engine suddenly
    stopped. The blade continued to spin until it slowed to a stop. It did
    not strike any objects. It was working fine up to this point.

    When I attempt to start the mower by pulling the string, the blade
    will
    spin quietly, but I do not hear the engine try to engage.
    Additionally,
    it feels "loose" when I pull the string; previously, I could hear the
    engine cranking, but not anymore.

    I'm not very experienced with lawn mower or small engine repair, but I
    did some basic troubleshooting by looking at guides on the web. The
    flywheel key, and the blade adaptor key both seem to be intact. The
    gas
    is fresh. Oil was recently filled.

    My mower is a Craftsman, model 143.996504 with a 6.5 Eager-1
    (Tecumseh)
    4-cycle engine (917.377431).

    Any ideas?

    Thanks.
    Stormin Mormon, Aug 19, 2006
    #6
  7. Sound advice.
    "Don Young" <> wrote in message
    news:...
    >
    > <> wrote in message
    > news:...
    >> Hi.
    >> Yesterday while I was mowing the lawn, my mower engine suddenly
    >> stopped. The blade continued to spin until it slowed to a stop. It did
    >> not strike any objects. It was working fine up to this point.
    >>
    >> When I attempt to start the mower by pulling the string, the blade will
    >> spin quietly, but I do not hear the engine try to engage. Additionally,
    >> it feels "loose" when I pull the string; previously, I could hear the
    >> engine cranking, but not anymore.
    >>
    >> I'm not very experienced with lawn mower or small engine repair, but I
    >> did some basic troubleshooting by looking at guides on the web. The
    >> flywheel key, and the blade adaptor key both seem to be intact. The gas
    >> is fresh. Oil was recently filled.
    >>
    >> My mower is a Craftsman, model 143.996504 with a 6.5 Eager-1 (Tecumseh)
    >> 4-cycle engine (917.377431).
    >>
    >> Any ideas?
    >>
    >> Thanks.
    >>

    > The other posters have some good advice, but from your description it
    > sounds possible to me that your engine has a connecting rod broken at the
    > crankshaft end. That is based on engine spinning freely without any
    > sounds. The engine is likely beyond economical repair.
    >
    > There are some other possibilities, such as a valve being stuck open, that
    > are easily repaired. If it spins over easily there can be no compression.
    > I would have someone knowledgeable have a look at it if possible.
    >
    > Don Young
    >
    >
    John Lawrence, Aug 20, 2006
    #7
  8. Guest

    a broken connecting rod would be memorable noisey event, short but
    exciting.

    sounds more like a stuck valve, thats occured here
    , Aug 20, 2006
    #8
  9. Oren Guest

    On 20 Aug 2006 12:09:36 -0700, "" <>
    wrote:

    >a broken connecting rod would be memorable noisey event, short but
    >exciting.


    Nothing like the sound a "knocking rod", spun rod bearing, or broke
    valve.

    >sounds more like a stuck valve, thats occured here


    Easily checked at the tappet filter / crank breather (if this model
    has one) - remove it and pull the cord...the valves should move and
    easily viewed. The easy way; pull the plug wire and plug, determine
    which digit goes into the plug hole. Rotated through all four
    strokes: intake, compression, power, exhaust - you can feel the intake
    pulling the finger, Compression stroke will blow the finger out.


    Oren
    Oren, Aug 20, 2006
    #9
  10. mm Guest

    On Sat, 19 Aug 2006 21:57:12 GMT, "Stormin Mormon"
    <cayoung61-&spamblock*> wrote:

    >Pull the spark plug wire off, and secure it well away from the spark
    >plug.
    >
    >Leave the plug in.
    >
    >Tip the mower on its side, and try to turn the blade backwards of the
    >usual direction.


    I thought with the plug in, the blade could kick back when released or
    when it slipped out of one's hand. Not enough to cut off a finger,
    but enough to hurt, no?

    And the engine won't start because the spark plug wire is off and
    "secured" "well away", if it really is. The first time, it probably
    will be. The second or third time, one might forget. And I used to
    hook the wire to the fuel line, which in an old mower was a convenient
    place, but sometimes it sprang loose and went back to within a quarter
    inch of the plug, close enough for the engine to run.

    And anyone who is pushing the blade backwards might want to push it
    forwards too, not realizing it would be more likely to start.

    One could use a stick to push the blade backwards. God only gave us
    10 fingers.

    >If it spins freely, scrap the mower, and get another one. If it binds
    >and gets hard to turn at one or two places in the revolution, then you
    >have compression. Proceed to look for other problems.
    mm, Aug 21, 2006
    #10
  11. mm Guest

    On Sun, 20 Aug 2006 12:58:40 -0700, Oren <> wrote:

    >On 20 Aug 2006 12:09:36 -0700, "" <>
    >wrote:
    >
    >>a broken connecting rod would be memorable noisey event, short but
    >>exciting.

    >
    >Nothing like the sound a "knocking rod", spun rod bearing, or broke
    >valve.
    >
    >>sounds more like a stuck valve, thats occured here

    >
    >Easily checked at the tappet filter / crank breather (if this model
    >has one) - remove it and pull the cord...the valves should move and
    >easily viewed.


    I think I had one once, where the pin holding the spring in place had
    come out. One spring of the two was fully extended, even more than
    needed to close the valve. The spring was iirc loose, because nothing
    held it in place at one end. At the time, I would never spend enough
    for a valve spring tool, but a shop could have fixed it in a few
    minutes I guess.


    The easy way; pull the plug wire and plug, determine
    >which digit goes into the plug hole. Rotated through all four
    >strokes: intake, compression, power, exhaust - you can feel the intake
    >pulling the finger, Compression stroke will blow the finger out.
    >
    >
    >Oren
    mm, Aug 21, 2006
    #11
  12. Ether Jones Guest

    professorpaul wrote:
    > Engines basically don't run for one of two reasons:
    >
    > 1. Fuel
    > 2. Spark



    THREE reasons:

    1) fuel

    2) spark

    3) compression


    >From the OT's description, it sounds like #3.
    Ether Jones, Aug 24, 2006
    #12

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