1958 10 horse Johnson carb rebuild

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  • May 15, 2019 at 10:14 pm #175344
    cron78
    Participant

      US Member - 2 Years

      I’m still struggling with the ’58 10 horse Johnson carb rebuild. Current issue is that the bushing #303947 is locked onto the low speed needle better than if it was cast in place. The needle with bushing is in the pan in the photo (if I get the pic to upload). I soaked them overnight in carb cleaner, tried PB Blaster, tried heat, and tried pure muscle and the pliers are just peeling away the outside of the bushing and needle. Seems to be a lost cause. I rebuilt a ’56 7.5 carb a couple years ago and don’t remember a bushing like this. I thought about substituting a needle from one of my donor 5.5 HPs, but they are different sizes.

      What is the bushing for? What is the correct reassembly process if/when I get new ones?

      Also, the white corrosion(?) powder I mentioned in a post a couple days ago can be seen int he second photo (again, if it uploads) along with the gasket that appears to be rubber. Ever seen a rubber carb gasket? The high speed needle was locked into the carb by similar corrosion but some heat persuasion got them separated.

      Thanks for any advice.

      Dale

      May 15, 2019 at 10:56 pm #175352
      Geer Pyron
      Participant

        Dale,
        I;ve had a similar issue with a ’56 12hp Sea King. For me, the problem was that I couldn’t back the needle out of the carb body. It would just turn and turn but not back out. I found out that that bushing was threaded for the needle but just inserted into the carb body. Then the packing washers and nut held it in and still while the needle was screwed in. Maybe look inside the carb, where that needle goes and see if it is threaded for the needle (not just the packing nut) in there.
        But, I guess you asked how to get it off. I soak all my bare metal parts in laquer thinner. And am patient. Some one told me once that screw drivers that fit the screws and patience are the most important tools for rebuilding these ol’ motors.
        I just started my 6th rebuild. Its a ’54 10hp Seahorse. Similar. I’ll take a look at mine and see if it has that bushing thing.
        Geer

        JMGP

        May 16, 2019 at 12:23 am #175355
        crosbyman
        Participant

          Canada Member - 2 Years

          Don’t worry about the white powder stuff… a good cleaning and it is gone

          Joining AOMCI has priviledges 🙂

          May 16, 2019 at 2:28 am #175357
          frankr
          Participant

            US Member

            I really don’t have any non-destructive way to suggest, other than what you’ve already tried. But to answer the other questions, the bushing is the threads for the needle–that’s all. It is used on many carbs 10hp-up. Part # is 303947 if you are forced to destroy it. $$$$ at marineengine.com. I’ll bet there are lots of them in member’s goody boxes.

            To assemble it, put the packings on the needle, followed by the bushing screwed on only a few turns. Then the packing nut slipped onto the other end. Now, using the packing nut, push the whole assembly into the carb. Tighten the packing nut just enough to keep the bushing from spinning. Now screw the needle all the way in to gentle seating, and back out 1-1/2 turns and tighten the packing nut some more. Final adjustment when running as usual.

            If you must destroy the bushing, split it off the needle. I presume the bushing is easier to find/cheaper than the needle.

            May 16, 2019 at 9:56 am #175366
            cron78
            Participant

              US Member - 2 Years

              Yes, the white stuff cleaned out well with a wire brush on the Dremel. Thanks, Crosby.

              Frank, Thanks for the assembly order. That isn’t the order that I remember them coming out of the carb body. The guy I got the motor from had tinkered a bit with it but didn’t do much helpful other than get a new impeller in the lower unit.

              Dale

              • This reply was modified 4 years, 11 months ago by cron78.
              May 16, 2019 at 8:20 pm #175398
              cron78
              Participant

                US Member - 2 Years

                Next question…the small hole in the mating surface seen above the fuel connection on the bottom part of the carb is supposed to go through to the bottom of the carb where the #303041 small screw plug is, correct? It looks like it is a passageway. As you can see in the pic, it is slam packed with corrosion and I didn’t want to start “drilling” it out and destroy something that isn’t supposed to be a through hole. It looks like fuel has to move through this passage past the end of the high speed needle.

                Thanks for any confirmation one way or the other.

                Thanks,

                Dale

                May 16, 2019 at 8:46 pm #175400
                bobw
                Participant

                  US Member

                  Yes, that passage should be open. You said in a previous post you cleaned the white debris by using a wire wheel on a Dremel tool. Best way to clean a carburetor, including all the fuel passages is to let it soak in some carb cleaner solution. There are various products available for this. After a good bath, blow out all the fuel passages with an aerosol carb cleaner spray, but be careful – when you spray in one hole it will come shooting out another and could fly up right into your face. I wear safety glasses when doing this.

                  Bob

                  1937 Champion D2C Deluxe Lite Twin
                  1954 Johnson CD-11
                  1957 Evinrude Fastwin 18
                  1958 Johnson QD-19
                  1958 Johnson FD-12
                  1959 Johnson QD-20

                  “Every 20 minute job is only a broken bolt away from a 3-day project.”
                  "Every time you remove a broken or seized bolt an angel gets his wings."

                  • This reply was modified 4 years, 11 months ago by bobw.
                  May 16, 2019 at 8:57 pm #175406
                  cron78
                  Participant

                    US Member - 2 Years

                    Thanks Bob. I thought so. I soaked this thing overnight a couple days ago and still have issues. I have been using a thin wire to try to remove the corrosion enough to get spray through. Still have about a half inch to go on the side run. Bottom run of the passage is clear. I have read the others use a sonic cleaner. That might be what this carb needed.

                    Dale

                    May 16, 2019 at 9:28 pm #175408
                    bobw
                    Participant

                      US Member

                      Ultrasonic cleaners are great but I just use a mild solution of Pinesol in a crockpot. Works good for me.

                      Bob

                      1937 Champion D2C Deluxe Lite Twin
                      1954 Johnson CD-11
                      1957 Evinrude Fastwin 18
                      1958 Johnson QD-19
                      1958 Johnson FD-12
                      1959 Johnson QD-20

                      “Every 20 minute job is only a broken bolt away from a 3-day project.”
                      "Every time you remove a broken or seized bolt an angel gets his wings."

                      • This reply was modified 4 years, 11 months ago by bobw.
                      May 16, 2019 at 9:55 pm #175410
                      Geer Pyron
                      Participant

                        You got a late night if you’re gonna have that thing did for Quincy tomorrow!

                        JMGP

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