Fuel line from carb loses prime

Discussion in 'The Engine Bay' started by zackmoxley, Sep 17, 2016.

  1. zackmoxley

    zackmoxley Registered Member Premium Member

    Oct 26, 2013
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    las Vegas
    thats strange it didnt leak fuel. Ill take a look
    Ill start with the rubber fuel line replacement.
  2. diesel4me

    diesel4me 1 ton status Premium Member

    Jul 24, 2003
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    The mechanical fuel pump has built in check valves that are not only a must for it to pump period,but to hold the fuel from draining back into the tank--they could be faulty and working well enough to pump fuel,but not hold it with the engine off.
    Also if the diaphram in the pump has a pinhole or rupture it can still pump,but also let gas drain into the crankcase when the engine is off,and that can do nasty things to bearings & rings due to the oil being diluted..

    Even if the fuel did drain back,there should be plenty left in the float bowl to start and run the engine at least a minute also--perhaps the carb needs an insulating spacer to prevent heat soaking into the carb and boiling off the gas--ethanol gas evaporates rapidly when it gets too hot,much faster than the old leaded gas these engines were designed to run on..
  3. forest_peterson

    forest_peterson 1/2 ton status Premium Member

    Dec 10, 2013
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    Concow, CA
    Check that your choke is functioning correctly as a first stop. I had the hard start hot condition. There is a long thread where everyone tried helping me with this, the scope of the thread went all over the place. This link takes you to where the hot start problem is addressed, go a couple posts earlier to see the lead up and read from this post on and eventually the hot start problem is solved. https://ck5.com/forums/threads/quad...d-accelerator-pump.317338/page-5#post-3505478

    EDIT: Rereading that thread looking for the hot start problem and now I recognize everyone helping me - at the time it was all new people, thank you guys for the help; still runs good and no more q-jet shenanigans.
    Last edited: Sep 24, 2016

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