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    Carb Sync question

    Have a question on Carb Syncing on 82 gs650gl, Ive included picture from Suzuki manual. So it shows sync order as 2/1/4 (a/b/c as pictured) I know where those adjustment screw are located My question is related to carb 3 (base carb) am I correct in thinking that the base adjustment is done with the throttle stop then proceeding in the order. So throttle stop to get base line read then onto 2 then 1 then 4. then final adjustment to pilot screws? Thanks in advance.
    carb sync order.jpg
    1983 GS650GL Not running when I bought it. runs great now
    Engine- Carb Cleaned, Valve Adj, Ignition Mod, balanced carbs, Polished/Painted engine, Exhaust wrapped
    Frame & Wheels painted, rebuild brakes/masters, Fixed Tach/Spedo, Sonic Springs in the Front, New handle bars w/bar end mirror/turn signals
    Still To-Do?
    Fuel sending unit, Fuel tank paint job?, LED headlight?, Seat falling apart, Solutions?, Changing look of the rear of bike, Seat, Brake/turn-signals

    #2
    Originally posted by DrDankNuggs View Post
    Have a question on Carb Syncing on 82 gs650gl, Ive included picture from Suzuki manual. So it shows sync order as 2/1/4 (a/b/c as pictured) I know where those adjustment screw are located My question is related to carb 3 (base carb) am I correct in thinking that the base adjustment is done with the throttle stop then proceeding in the order. So throttle stop to get base line read then onto 2 then 1 then 4. then final adjustment to pilot screws? Thanks in advance.
    [ATTACH=CONFIG]61022[/ATTACH]
    Your understanding is pretty much spot-on.

    Connect the gauges. Start the bike and warm it up enough so you don't need the "choke".
    Use the idle adjuster under the carbs to get the idle speed to 15-1700 RPM (this helps smoothe out the pulses).
    Use the sequence that you posted. Sync #2 to #3. Note that when you do that, the other levels might change a bit, too. When you have 2 and 3 balanced, adjust #1 to match. Don't worry about that "half a ball" difference shown in the factory manual. If #1 is a bit higher than 2 and three, it will sort of match the manual, but don't go over 2cm difference. That is the measure of "half a ball". Most of us just go straight across on all four. When #1 is done, move to #4. When you are done, blip the throttle a few times to make sure nothing changes.

    .
    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


      #3
      Originally posted by Steve View Post
      Your understanding is pretty much spot-on.

      Connect the gauges. Start the bike and warm it up enough so you don't need the "choke".
      Use the idle adjuster under the carbs to get the idle speed to 15-1700 RPM (this helps smoothe out the pulses).
      Use the sequence that you posted. Sync #2 to #3. Note that when you do that, the other levels might change a bit, too. When you have 2 and 3 balanced, adjust #1 to match. Don't worry about that "half a ball" difference shown in the factory manual. If #1 is a bit higher than 2 and three, it will sort of match the manual, but don't go over 2cm difference. That is the measure of "half a ball". Most of us just go straight across on all four. When #1 is done, move to #4. When you are done, blip the throttle a few times to make sure nothing changes.

      .
      Thanks Steve You're a gentleman and a scholar.
      I did end up going a head and replaced valve shims as I listed in the email went on with out a hitch, now every valve is within .06-.08 except ex4 which was a little tighter at .04, Also bought a extra 2.60 shim for the inevitable tightening of ex4.
      Hopefully last question regarding syncing, should I put too much stock into the numbers on the gauge (see pic) they are all floating around 30 but according to gauges it should be 45-55 (normal motor) or ignore that and just be concerned with getting them synced regardless of what the cheap Chinese gauge says is normal.
      vac gauge face.jpg
      1983 GS650GL Not running when I bought it. runs great now
      Engine- Carb Cleaned, Valve Adj, Ignition Mod, balanced carbs, Polished/Painted engine, Exhaust wrapped
      Frame & Wheels painted, rebuild brakes/masters, Fixed Tach/Spedo, Sonic Springs in the Front, New handle bars w/bar end mirror/turn signals
      Still To-Do?
      Fuel sending unit, Fuel tank paint job?, LED headlight?, Seat falling apart, Solutions?, Changing look of the rear of bike, Seat, Brake/turn-signals

      Comment


        #4
        Pay no attention to the actual numbers. Hopefully that is just one gauge of a set of four.

        If that <is> a set of four, hopefully you made a tubing manifold that will allow you to connect all four gauges to the SAME vacuum source at the same time. That will allow you to see what differences there might be between the gauges. Better-quality gauges will allow you to tweak the needle so they will all read the same. Then, when you put them on the four separate sources in the manifolds, you will know that any difference will be due to the cylinders and carbs, not any differences in the gauges.

        If that is just the one gauge, don't even bother trying to sync the carbs. Wait until you have a proper set. And, for the money, the Carbtune Pro is probably cheaper than the set of four Motion Pro gauges that look like the one you posted.

        It is more important that the carbs are all equal, not what the actual numbers are.

        .
        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


          #5
          lol yeah it is a set of four, I was just trying to get a closeup where the dial was legible.
          I didn't have fittings to create a manifold to do them all at the same time, however I did go threw the gauges individually, hooked up a mighty vac bleeder pulled a known vacuum on the gauge and adjusted the needle to read the known vacuum. went through and calibrated each gauge individually, then went back threw a second time to confirm the gauges maintained calibration. I thought that would be good enough, but I could be wrong.
          1983 GS650GL Not running when I bought it. runs great now
          Engine- Carb Cleaned, Valve Adj, Ignition Mod, balanced carbs, Polished/Painted engine, Exhaust wrapped
          Frame & Wheels painted, rebuild brakes/masters, Fixed Tach/Spedo, Sonic Springs in the Front, New handle bars w/bar end mirror/turn signals
          Still To-Do?
          Fuel sending unit, Fuel tank paint job?, LED headlight?, Seat falling apart, Solutions?, Changing look of the rear of bike, Seat, Brake/turn-signals

          Comment


            #6
            Just to be SURE, get some T fittings and some hose at Auto Zone so you can connect them all at the same time.

            It just eliminates one more variable to KNOW that they are all reading the same.

            Oh, ... this is not a one-time thing. You will need to do this every time you use the gauges.

            .
            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


              #7
              Welcome to the site!

              Put your year and model in your signature so we'll always know.
              1982 GS1100E V&H "SS" exhaust, APE pods, 1150 oil cooler, 140 speedo, 99.3 rear wheel HP, black engine, '83 red

              2016 XL883L sigpic Two-tone blue and white. Almost 42 hp! Status: destroyed, now owned by the insurance company. The hole in my memory starts an hour before the accident and ends 24 hours after.

              Comment


                #8
                Does the order of sync described above (carb 3 baseline, then 2,1,4) apply to VM carbs? My '78 manual doesn't specify, though it says to start with #4 (but maybe only because it uses that one to calibrate the gauge?) then correct any of the other three not matching.
                Thanks.
                1978 GS 750 E
                1979 XS11 Standard
                1973 CB450

                Comment


                  #9
                  VM carbs are different because each individual carb has it's own adjuster.

                  For CV carbs the order is to align 2 and 3 first, using the center adjuster, then align the outer carbs, 1 and 4, to the baseline established by 2-3. It doesn't matter which order between 1 or 4 since these are independent to each other.
                  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

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