Mark 25 Fuel Issues

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  • August 27, 2017 at 9:42 pm #8049
    cheetahgod
    Participant

      Was able to start the mark 25. However it kept dying out due to a lack of gas. When squeezing the priming ball gas shoots out of carb.
      Could it be the fuel pump or float? Also motor kept backfiring and not starting. I switched the spark plug wires and it fired up. On one of the spark wires there is a tag that says top but the motor only starts when this wire is on the bottom. Bad coils or wrongly labeled?

      August 27, 2017 at 10:01 pm #63925
      RICHARD A. WHITE
      Participant

        Lifetime Member

        Do you have a manual?, I can assure you, if you go step by step on setting it up and going thru the ignition and carb, you will LOVE the performance of that motor.

        http://www.richardsoutboardtools.com
        classicomctools@gmail.com

        August 27, 2017 at 10:14 pm #63927
        cheetahgod
        Participant

          Yeah I have the manual

          August 27, 2017 at 11:04 pm #63931
          RICHARD A. WHITE
          Participant

            Lifetime Member

            Good start, then pull the carb, go thru it following the manual, then that possible issue will be removed, also the manual shows the ignition and how it is to be set along with the proper mag timing, and that needs to be set right..

            You will love this motor… I have the 1956 Electric start model… very good motor to run..

            http://www.richardsoutboardtools.com
            classicomctools@gmail.com

            August 28, 2017 at 1:17 am #63937
            jeff-register
            Participant

              US Member

              Don’t forget lines & pumps. Found a few missing gaskets under the check valves. Fuel system demands to be clean. Take your time & read please.
              Merc’s are known for burnt pistons. Pay close attention to the book. Don’t run lean!!!!

              August 28, 2017 at 1:39 am #63939
              cheetahgod
              Participant

                The gaskets and fuel lines look new. Any idea why the carb wouldn’t be sucking gas?

                August 28, 2017 at 10:49 am #63944
                chuckw
                Participant

                  US Member

                  Had a similar issue. When I took the carb apart the little spring on the top of the float had hung up the float lever so no gas was getting to where it was supposed to.

                  August 28, 2017 at 3:02 pm #63954
                  cheetahgod
                  Participant

                    ok thanks

                    August 28, 2017 at 5:18 pm #63959
                    jeff-register
                    Participant

                      US Member

                      Check valves may be backwards too. Fuel connector sucking air. Tank vented? blow into the supply port of the carb level & upside down to if the float is free.

                      September 20, 2017 at 2:59 am #65151
                      cheetahgod
                      Participant

                        Went through the carb and fuel pump. Replaced needle and seat. Replace check valves and various gaskets. Cleaned carb.
                        Now it seems the engine is flooding. When I pull start it gas spews out from carb.
                        Noticed a leak on my connector on the fuel line with the primer bulb but I don’t think that is the issue.
                        Help please

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