1971 mercury 75

Home › Forum › Ask A Member › 1971 mercury 75

Viewing 7 posts - 1 through 7 (of 7 total)
  • Author
    Posts
  • April 14, 2021 at 6:50 pm #236368
    Geer Pyron
    Participant

      US Member

      Hey,
      I’ve been working on a 1971(?) Mercury 75. I’ve gotten it all done and running. Took it for a two hour tour the other day. I’m real happy with it.
      But it’s a real pain to start. It takes ten pulls! It’s fine after that. I can’t seem to find any specific information on tuning.
      Does anyone have any suggestions for making it easier to start?
      Thanks,
      G

      JMGP

      April 14, 2021 at 7:23 pm #236375
      dave-bernard
      Participant

        US Member

        choke problem?????? make sure it fots tight

        April 14, 2021 at 8:34 pm #236381
        Geer Pyron
        Participant

          US Member

          Dave,
          Thanks for the input.
          The choke is missing a spring.
          It needs two. One for returning the choke to open position and one for….
          I’ll assume it’s to hold the plastic choke valve to the carb body.
          That’s the one I’m missing.
          I was hoping to get by without it, but your post is the third time I’ve read about the choke having to fit tight.
          Thanks,
          G

          JMGP

          April 14, 2021 at 10:03 pm #236389
          dave-bernard
          Participant

            US Member

            try to press it with your finger while starting cold and see how it works . get the spring.

            • This reply was modified 4 years, 7 months ago by dave-bernard.
            April 15, 2021 at 5:38 am #236407
            billw
            Participant

              US Member

              Make that four times. They have to fit snugly when closed. Been there, done that.

              Long live American manufacturing!

              April 15, 2021 at 9:39 am #236412
              Geer Pyron
              Participant

                US Member

                Yep.
                That was it. Tried starting it this morning as I had been. Three pulls. No go.
                The choke looked snug against carb body. But then I pressed it against the carb body while trying to start. Fired up immediately, like half pull immediately, like after it’s been running for a bit immediately. Nice.
                But as a side note, water wasn’t coming out of tell tale with any vigor. A trickle only no matter what rpm despite having a new everything.
                Found out the 90 degree nipple on top of block was bottoming out on whaterever is inside. I cut a 16th, a few threads worth, off and now it spews like it should.
                Damn, now I gotta call that old man and tell him it’s done.
                Maybe one more “test run”.
                Ha!
                Thanks again
                G

                JMGP

                April 15, 2021 at 10:41 am #236414
                seakaye12
                Participant

                  US MEMBER PAY BY CHECK

                  Sounds like you’ve got it whipped! Always nice to have an easy fix. For others with hard starting issues I would also mention the need for good crankcase sealing. Are the upper and lower crankshaft seals in good condition? Also….there is another part that gets replaced …the crankcase purge check valve Mercury #21-64871A 1

                  This is an interesting video. I’d be interested in hearing experienced Mercury guys talk about this person’s techniques…..

                  https://youtu.be/FausN8EWzPE?t=1166

                  That link takes you to the portion where he tests the check valve.

                • Author
                  Posts
                Viewing 7 posts - 1 through 7 (of 7 total)
                • You must be logged in to reply to this topic.