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Twin 2001 250ox66 one cranks one try's

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  • Twin 2001 250ox66 one cranks one try's

    Any suggestions
    I have twin 250 ox66's 2001 year models. One cranks and runs fine.
    The other fires but sounds like only on about two cylinders ,maybe.
    All cylinders have 118 psi compression, New plugs, plugs are firing.
    Sounds like a fuel problem.
    I crank both engine and run them for about 10 minutes each one a week while not in use. It ran fine the last time I ran it.???

  • #2
    check the VST for water or debris. does the HP pump come on at key on ?

    Comment


    • #3
      Is the vst the tank the high preasure pump is in? If so removed that cleaned and made sure pump was running.

      Comment


      • #4
        does it run at key on?
        did you find any debris?
        you really need to monitor fuel rail pressure.

        Comment


        • #5
          Yes, the pump runs at key on.
          Yes, I found what I call sugar from ethanol. I am vigilant with staybil.
          I have checked the screens in the ends of the injectors also. They was all clean.
          I have not checked rail preasure. I'm not sure what type of gauge to hook to the schraider valve.
          I'm pretty sure it's a fuel issue, because I can throttle wide open while cranking and it will almost run on like maybe two cylinders.

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          • #6
            and that's why rail pressure must be monitored.
            much above 40 psi and that motor runs like crap.
            at 50 psi it wont idle.
            much more than 55 its simply to rich to run.

            much below about 30 psi and all it will do is idle. much below about 20 psi it quits running.

            same size valve fitting as a bicycle.

            bet ya did not check the return filter.

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            • #7
              No, I didn't check the return filter.
              Honestly, I didn't know it had one. Where is it?
              So, are you saying use a regular tire preasure gauge.

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              • #8
                you must use a guage that is fuel resistant and capeable of 70 PSI or so without failing.

                the return filter is under the pressure regulator, if it clogs it spikes fuel pressure.
                did you physically remove and clean the injector filters ?

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                • #9
                  Yeh, I removed the green filter from each injector and cleaned. They wasn't clogged or dirty.
                  I'll get a gauge capable and check the rail preasure.
                  I'll also check and or replace the return filters in both engines.
                  Thanks for the input and I'll let you know what I find later this week.

                  Comment


                  • #10
                    if rail pressure is in spec or below spec its not a return filter issue so why bother?

                    see how this troubleshooting thing is?
                    you eliminate one thing at a time.

                    if rail pressure is good test injectors.
                    but without correct railpressure it simply will not and cannot run correctly I don't care what else is good or bad.

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                    • #11
                      That makes since.
                      Can the injectors be tested by me or will I have to take them in to my dealer?

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                      • #12
                        you can test the resistance with a multimeter.
                        you can test to see if they "click" with a jumper lead and a paper clip if you understand how its wired and how they fire.
                        to flow test them you will have to find an injector shop.

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                        • #13
                          Notice he said injector shop not the dealer shop
                          two different places

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                          • #14
                            trace the injector harness back to the port head.
                            unplug the 6 pin connector.
                            using a jumper lead and a paper clip.
                            turn the key on.
                            ground one end of the jumper.
                            touch the other end to each pin of the injector harness briefly.
                            you should hear the injector click.

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                            • #15
                              I bought a fuel preasure test gauge from Snapon today and checked the rail preasure. It was 0. The pump does run for about maybe 5 seconds then stops.
                              Turn the key off and back on it does the same thing. I guess the fuel pump is just bad.
                              I did prime the bulb then spun the engine over.

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