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man vs screw (an epic saga)

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    man vs screw (an epic saga)

    I have a 1982 GS850gl that was running, but very slowly. I got lots of good advice from you fine folks here at GSR and began taking the necessary steps to correct it. I got tons of great info, especially the carb rebuild pics. I ordered a set of new intake boots and an o-ring kit from Robert Barr (thanks! a total life saver). I got my workbench cleared off, got out my wife's camera and began to slowly and methodically rebuild my carbs. It was great. I love being in my garage. I was really enjoying it UNTIL ... I got to the mixture screw on carb #2.
    The guy I bought it from (2nd owner) told me that it had been sitting for many years (inside thankfully) when he got it. He brought it to a bike shop and had the carbs "done". Looking at the gouged out screw slot on the #2 mixture screw I was reminded of the part in Zen and the Art of Motorcycle Maintenance where he makes the mistake of going to the shop and has his bike screwed up by careless mechanics.
    At first I tried to use the right sized screwdriver and some PB Blaster to get it out but there was not enough left to grab. Next, and this is very dumb, I got out my drill and an extractor bit. I've never had much luck with these and only now do I know why. I used my punch to mark the center of the screw and drilled out a small hole. Next, I put in the extractor, set my drill in reverse and SNAP! a small set back just turned into a huge problem that might only be solved with dynamite! Extractors are made from hardened steel that is very brittle and impossible to drill through. Once you've got a piece of one stuck somewhere the only way I know to get it out is to drill away the surrounding metal. I was reluctant to jump right into this task because this is a sure way to ruin the threads of what ever you are drilling the screw out of. I did a little research, first here, then at Dan's motorcycle repair. His sight is great! ( http://www.dansmc.com/index.htm ) I read about the old crazy glue on the end of a bolt trick and tried it with no luck. Next I learned Dan's technique for using extractors, instead of using the drill he traps them in with a hammer then turns them by hand. Sure wish I had a time machine.
    Anyway, after striking out with the crazy glue, I said a prayer and started drilling away the screw. After lots and lots of drilling I finally got the little piece of the extractor out and drilled out the mixture screw. The threads in the carb body were wrecked but I suspect they were crossed to begin with. To fix this I got a tap and die kit. Unfortunately the threads on the mixture screw are 6mm x 0.5 pitch. This not a very common size tap and I had to special order one.
    My plan for when it gets here is to coat the old threads with a thin layer of JB Weld, drill it out and cut threads with my new tap. If this works I will let you all Know. If not I'll be buying a new #2 carb body.
    I wonder if this is how Captain Ahab felt?

    #2
    I know this is a day late and a dollar short here, but I have had success in using a small jewelers' flat head screwdriver to recut a slot in the top of mixture screws.

    The corner of the screwdriver blade must be 90 degrees, and sharp. It can be worked from one side of the screw to the other, back and forth in the old slot, with significant pressure applied to score out a new slot.

    I had to do this on a buddy's mixture screw on his yamaha (which uses BS32 carbs!).

    It only took a few minutes, and left a nice pressure deformity on my thumb for an hour, but it did the job, and we were able to remove the stuck mixture screw with a little PB Blaster, and a properly fitting screwdriver.

    I am sure all of us are curious to know how the JB weld will work out, it could be the fix many of us are looking for to resurrect some carb bodies for spares.

    Good job, and please do keep us informed.

    Comment


      #3
      Long before I ever even think about using an extractor on a carb screw, I grab my Dremel tool with a large cut-off disk and cut a slot down the tower, into the head of the screw. The new slot in the top of the screw allows you to wind it right out, and the slot in the tower does no harm.

      Here, you can see slots in both, #1 and #2:



      sigpic
      mine: 2000 Honda GoldWing GL1500SE and 1980 GS850G'K' "Junior"
      hers: 1982 GS850GL - "Angel" and 1969 Suzuki T250 Scrambler
      #1 son: 1986 Yamaha Venture Royale 1300 and 1982 GS650GL "Rat Bagger"
      #2 son: 1980 GS1000G
      Family Portrait
      Siblings and Spouses
      Mom's first ride
      Want a copy of my valve adjust spreadsheet for your 2-valve per cylinder engine? Send me an e-mail request (not a PM)
      (Click on my username in the upper-left corner for e-mail info.)

      Comment


        #4
        I like the jewelers screwdriver technique, you could always cut down into the tunnel if the first attempt fails.

        One other thing to try is heat on the carb body, helps break down the chemical bond holding the screws in place. And NEVER use an extractor unless you are highly experienced with them...for obvious reasons.
        Ed

        To measure is to know.

        Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182

        Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846

        Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf

        KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection

        Comment


          #5
          Wow, that really sounds frustrating I've read where you can also try the freeze spray on the screw, kinda doing the same as adding heat to the body, to break the bond and make it easier to turn.

          Comment


            #6
            I did the same damn thing..

            I very carefully drilled on either side of the broken extractor with a 1/16" bit until I could get under the extractor with a pick and pry the tip out.. Now I had a large slot but she still wouldn't budge..


            Step 2.. Toss it in the carb dip for 3-4 days.. when it came out you could turn the air screw out without much effort.

            As for the buggered threads.. JB might work.. I've used it on a holley double pumper base before to repair a stripped accelerator pump stud bore.

            Just don't get any on the taper at the bottom..

            I've wondered if you could melt in some Aluminum solder paste and tap that..

            Comment


              #7
              Originally posted by sschering View Post
              Step 2.. Toss it in the carb dip for 3-4 days.. when it came out you could turn the air screw out without much effort.
              I tried that once. It might work after 3-4 days, but I can guarantee that SEVEN days does not work.

              I still recommend the slot cut into the tower and the top of the screw.

              .
              sigpic
              mine: 2000 Honda GoldWing GL1500SE and 1980 GS850G'K' "Junior"
              hers: 1982 GS850GL - "Angel" and 1969 Suzuki T250 Scrambler
              #1 son: 1986 Yamaha Venture Royale 1300 and 1982 GS650GL "Rat Bagger"
              #2 son: 1980 GS1000G
              Family Portrait
              Siblings and Spouses
              Mom's first ride
              Want a copy of my valve adjust spreadsheet for your 2-valve per cylinder engine? Send me an e-mail request (not a PM)
              (Click on my username in the upper-left corner for e-mail info.)

              Comment


                #8
                Go to the parts wanted section and find another #2 carb off either a 750 or 850.
                Ask about stuck mixture screws first before using never outs. Even with the buggered head I could of saved that carb and would of been more than willing to explain to you how it's done.
                A search also would of brought the other one-hundred times I've covered it.
                1983 GS 1100E w/ 1230 kit, .340 lift Web Cams, Ape heavy duty valve springs, 83 1100 head with 1.5mm oversized SS intake valves, 1150 crank, Vance and Hines 1150 SuperHub, Star Racing high volume oil pump gears, 36mm carebs Dynojet stage 3 jet kit, Posplayr's SSPB, Progressive rear shocks and fork springs, Dyna 2000, Dynatek green coils and Vance & Hines 4-1 exhaust.
                1985 GS1150ES stock with 85 Red E bodywork.

                Comment


                  #9
                  Originally posted by chef1366 View Post
                  Go to the parts wanted section and find another #2 carb off either a 750 or 850.
                  Ask about stuck mixture screws first before using never outs. Even with the buggered head I could of saved that carb and would of been more than willing to explain to you how it's done.
                  A search also would of brought the other one-hundred times I've covered it.
                  Wow, that's a little rough for a junior member.
                  Current Bikes:
                  2001 Yamaha FZ1 (bought same one back)

                  Comment


                    #10
                    Originally posted by ddaniels View Post
                    Wow, that's a little rough for a junior member.
                    Not my intent
                    sorry
                    1983 GS 1100E w/ 1230 kit, .340 lift Web Cams, Ape heavy duty valve springs, 83 1100 head with 1.5mm oversized SS intake valves, 1150 crank, Vance and Hines 1150 SuperHub, Star Racing high volume oil pump gears, 36mm carebs Dynojet stage 3 jet kit, Posplayr's SSPB, Progressive rear shocks and fork springs, Dyna 2000, Dynatek green coils and Vance & Hines 4-1 exhaust.
                    1985 GS1150ES stock with 85 Red E bodywork.

                    Comment


                      #11
                      Originally posted by ddaniels View Post
                      Wow, that's a little rough for a junior member.
                      Naw, he has a good point. If I had been a little more patient and done some homework first, I would be riding right now instead of waiting for my machinist buddy to save the day.
                      Let this be a lesson to the rest of you new GSers; It's better to ask before doing a job, than to whine after screwing one up.

                      Comment


                        #12
                        At the risk of hijacking the thread or raising somone's ire, it would be helpful to know how one could search for the thread that would solve the problem.

                        I have used the search feature and have had mixed results. Would I just put in "stuck mixture screws"?
                        1980 GS550L

                        Comment


                          #13
                          Originally posted by goggles View Post
                          At the risk of hijacking the thread or raising somone's ire, it would be helpful to know how one could search for the thread that would solve the problem.

                          I have used the search feature and have had mixed results. Would I just put in "stuck mixture screws"?
                          It seems to me that Steve's solution right here on this thread would be the easiest way to take care of the problem. The only reason I have created such a tangled mess with mine is that I didn't ask for help first.

                          p.s. my buddy Honey Osbourne, (a dang metal magician!) has plugged and machined the carb body, and I'm picking it up today. I'll let you all know how it works after I get it dialed in.

                          Comment


                            #14
                            So, I got my carbs put back together and back in my bike. The good news is that it works and it runs a hell of a lot better than it did before I took it apart. The bad news is after refitting the mixture screw, it would not screw all the way back in so I could not get them to sync. It's not perfect but will have to do till I can afford a new carb body.

                            Comment


                              #15
                              Originally posted by joseleary View Post
                              Naw, he has a good point. If I had been a little more patient and done some homework first, I would be riding right now instead of waiting for my machinist buddy to save the day.
                              Let this be a lesson to the rest of you new GSers; It's better to ask before doing a job, than to whine after screwing one up.

                              I wholeheartedly agree with you on this one.

                              Comment

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