Welcome Guest - Sign Up today
Welcome Guest - Sign Up today



Help Tip: If you have a question that has not been answered to your satisfaction in the archives, it is always best to start a new thread of your own. By starting your own thread, you will receive the maximum number of views by forum members.

Please note this topic has been inactive for 90 days. For the best results, please start a new topic.

Thank you all in advance for doing your part in helping iboats run a smooth ship.

Additional forum rules linked below.
See more
See less

Collapsing fuel pump ball

  • Filter
  • Time
  • Show
Clear All
new posts

  • Collapsing fuel pump ball

    Ok yesterday I diagnosed a lack of fuel being able to be primed to the engine. After removing the line from the engine to the ball it reassured my assessment as the diaphragm most have collapsed.

    Today I replaced the ball and it primed ok but never could get the ball tight. The ball would eventually return to its non-collapsed state at idle. Under higher throttle while running the ball would collapse. I figured this may be putting my fuel pump under additional strain so I returned to the dock. Please advise of any remedies or if I have one at all. Thanks in advance.

    Motor specs:
    2002 Yamaha 150 hp, 2-stroke, carbureted, txra

  • #2
    Re: Collapsing fuel pump ball

    Sounds like a restriction in fuel flow from the tank to the primer bulb, hay.

    There should be an anti-siphon valve in the tank pickup.. .you don't tell us what sort of tank you have. . .that could be clogged or stuck.

    The pickup tube itself may be resricted by debris.

    The vent for the tank might be restricted or blocked.

    Good luck.


    • #3
      Re: Collapsing fuel pump ball


      I have a 90 gallon tank below the deck in my 2002 21' Parker CC, SE model.

      Another issue I did not report was I had an extremely hard time fueling the boat. I added an additional 25 gallons to the existing supply of @ 40 gallons from the late summer/fall. The pump kicked off more than usual and gas spit back even when the handle was depressed only 50%.

      Is the anti-siphon located on top of the tank? If so, I think I have access through the deck plate.

      If the pick up tube is blocked, where would I blow compressed air through?

      I have a fuel vent as well on the hull.



      • #4
        Re: Collapsing fuel pump ball

        The pump kicking off so often suggests that your vent may be restricted, Hay.

        Don't know your boat, but Parker is of a quality that I think you will have an anti-siphon valve at the top of the pickup. . .where your fuel line connects.

        I would also expect that the pickup is attached to a small plate bolted to the top of the tank and integral with the anti-siphon valve.

        The AS valve will prevent you just blowing air in the connector for the fuel line. You will need to extract the whole "extractor" assembly to clean the pickup screen.

        Understand, please, that I don't know your boat and the above is based on experience with a lot of different boats. Consider it generic.


        • #5
          Re: Collapsing fuel pump ball

          try buying a whole new fuel line, i assume it is the simple kind where you just connect one end to the tank and the other to the eigine. Lines get stiff and go bad, and they are cheap. When you bulb sucks the sides together, and you can not prime it anymore, try dis-conecting the hose from the engine, and putting it right back. This should let air into the bulb, and let you start pumping again.

          it may just be a bad seal on the line.
          16 ft runabout w/ 70 hp evinrude
          26 ft grampain sailboat


          • #6
            Sign up today
            Re: Collapsing fuel pump ball

            I have had better luck with the Yamaha bulbs and their fuel hose is great. and also sounds like you may have a vent issue on the fuel inlet and the ck ball in the barb on the tank could be rusting and causing a issue with fuel restiction