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  1. #1
    dkmc is offline Diamond
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    Default OT- Propane forklift problems.......goes lean.....velocity govener bad??

    Velocity Governor question*

    ......but read the symptoms first...


    Propane forklift started running rough and stalling, restarts got harder and longer till
    the thing would only just fire a couple times but not start up.

    Had an old BEAM regulator and carb.
    Since I got the machine 3-4 years ago, I knew the regulator had problems because
    when you turn the key 'on' the fuel solenoid clicks, and you could hear propane hissing
    into the carb....even before the engine is running.

    SO.....got a new IMPCO regulator and carb, installed and mounted.

    STILL does the same thing with these new parts, although, it does idle and will
    rev up, but starts a lean out trend over 20-30 seconds and then stalls.

    Sometimes it seems rich enough and revs up crisply, and idles, then it 'goes lean', runs rough, stumbles and eventually dies after 20-30-60 seconds.


    There is a velocity governor under the carb........

    * My key question is, HOW DO THEY FAIL ?
    Is there a diaphragm inside that can break and let in a giant vacuum leak?

    Seems like there is an intermittent lean out condition going on here.


  2. #2
    BGunn is offline Plastic
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    Default

    How are you determining that it goes lean and not overly rich? You didn't mention the model or the engine used. Velocity governors "usually" fail so that you never know what will happen when you accelerate, example one time the engine may over rev and the next time it won't rev at all. And yes they can develop a vacuum leak but without knowing your particulars it is hard to say. The Impco that you bought, does it have the primer button or is it a Cobra series?

  3. #3
    dkmc is offline Diamond
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    Default

    1970 Model G83P-040 Chrysler slant 6

    Before it stalls and when it won't rev up when I open the throttle, I put my fingers across the
    air inlet of the carb and it improves the condition.

    Primer button on the Model J regulator......

    Are you suggesting it could stall just as easily from over-rich as too lean?

    I guess with propane it's a fine line.
    An O2 meter in the tail pipe would probably be a big help.

    dk

  4. #4
    BGunn is offline Plastic
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    As the engine starts to falter, push in on the primer button. If the primer button bottoms out you have a fuel delivery problem. If there is resistance as you push it in does the engine pick back up?

  5. #5
    dkmc is offline Diamond
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    Default

    Did that and there was resistance....but didn't pay close attention as to weather it helped or not.
    I don't think I got a good opportunity to watch the result of pushing the button.
    It was a lunch time session just to throw the new carb on....
    I will do this test tomorrow and report back.

    dk

  6. #6
    BGunn is offline Plastic
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    Default

    While you are at it, put a vacuum gauge on it and see what it reads.

  7. #7
    dkmc is offline Diamond
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    Default

    Will do.....

    Thank you for your ideas

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