Carb Rebuild on a ’58 7.5 Johnson

Home › Forum › Ask A Member › Carb Rebuild on a ’58 7.5 Johnson

Viewing 6 posts - 1 through 6 (of 6 total)
  • Author
    Posts
  • April 12, 2015 at 1:28 am #1172
    cron78
    Participant

      US Member

      Using the Sierra carb kit (18-7043) and the packing washers for the high and low speed needles are a hair too wide to fit easily into the threaded holes they should fit into that house the needles. Is that normal? Is it a problem? Should I hold out and order OMC carb kit that might be a little better quality and have packing washers that fit better? Do I force them down into the hole (I’m worried that they will tear off bits against the threads that can cause problems in the carb later.

      What have you guys done when encountering this issue?

      Thanks,

      Dale

      April 12, 2015 at 1:46 am #13757
      billy-t
      Participant

        I find the Omc kits work really well.

        April 12, 2015 at 1:52 am #13758
        wedgie
        Participant

          I soak them in 2 stroke oil for a while and then gently poke them into the "holes" with a blunt end of a dental pic. Then wind the needles through. They will take on a conical shape when you tighten up the packing nut and that should decrease the outside diameter a bit. Others may do it differently .

          April 12, 2015 at 2:21 am #13760
          cron78
          Participant

            US Member

            Thanks for the replies.

            I haven’t rebuilt a carb since my old ’75 Scirocco carb circa 1980. I suspected that perhaps they needed to be wet with something. They are hard and fragile. I split one just pulling it out of the hole after just pushing it in flush with the edge. Luckily there are a couple extra in the kit. I’ll give the two cycle soak a try.

            The old ones I pulled out for the rebuild just crumbled away. I guess they are akin to the old oakum packing in ship timbers.

            Already ordered an official OMC/BRP kit for next time.

            April 12, 2015 at 3:00 am #13762
            chris-p
            Participant

              I use a lot of the Sierra washers, they are supposed to be a touch big, as are the OEM ones.

              Just drop in hole, and use a blunt object, or large flat screwdriver to push them down to the bottom.

              April 12, 2015 at 11:36 am #13765
              frankr
              Participant

                US Member

                Start the packing on the needle, then screw the needle in till gently seated and back off correct # of turns. Now use the packing nut to shove the packing in the hole. The needle being in place prevents any shreds from entering the interior of the carburetor.

                The originals were stampings from gasket material. Back in those days, OMC gaskets had asbestos in them. That is why the packings seem slightly fiberous. Today’s packings are inferior to the old originals, but what ya gonna do?

              • Author
                Posts
              Viewing 6 posts - 1 through 6 (of 6 total)
              • You must be logged in to reply to this topic.