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Carb is *@%^$*@%^$*@%^$*@%^$ing gas like a cow

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    Carb is *@%^$*@%^$*@%^$*@%^$ing gas like a cow

    Hi there,

    Well, I just fixup my ignition problem and something else is failing...


    I was trying out the bike and the ignition timing, all was fine, I even did my first gas tank fillup.
    By the time I went back home, around 20 km later, I noticed a puddle of gas under the bike while opening the garage door.
    Uh-uh... not good...
    It looks like I did spread half of my gas tank around town... Lucky me it didn't drop on the exhaust or on the rear tire...


    So... my carb on the third cylinder is the one urinating all around (by the overflow of the bowl, from under the float bowl to be clear).
    Some more facts:
    - I did a "cleaned up" of the carbs when I got the bike. No it wasn't overnight dipped in cleaner, nor it was completly dissmembered. But I did disassembled the bottom section, floats needles etc..
    - My petcock is mess up. I tried repairing a leak and ended up likely gluing the diaphragm closed. So I'm running the bike on the Primer position as it's the only way to get gas running out of the poor thing. A replacement is in order at the stealer for the petcock.
    - As far as I know, carb adjustements is good. I have a nice idling, plenty of power on higher RPM, bike doesn't struggle on opening throttle, etc...

    So I've narrowed my problem to the float system, either the float needle doesn't seal properly, or the float get stock in the down position.

    Maybe the problem is running the bike on the primer side of the petcock? I mean, does the vacuum diaphragm would help in restraining the gas flowing in?

    So before I unmount the carbs, should I order some new float needle and seat? new floats?
    These needles weren't looking too bad when I cleaned them out 2 weeks ago...

    Any advice?

    Thanks guys!

    Frank
    Last edited by maisf; 08-26-2020, 12:58 PM.
    ------ Current rides: -----------------

    Honda CT70 K0 1970 complete restoration in progress
    Suzuki GS850 1979 as stock as could be... well except for the bars!
    Yamaha FJ-09 2016 with OEM saddle bags for long distance running and gunning
    Yamaha VStar 1300 2007 (wife's) for relaxing

    #2
    Well, looks like I shouldn't say %$?ssing...

    Is there a way to change the title of this post?

    lol
    ------ Current rides: -----------------

    Honda CT70 K0 1970 complete restoration in progress
    Suzuki GS850 1979 as stock as could be... well except for the bars!
    Yamaha FJ-09 2016 with OEM saddle bags for long distance running and gunning
    Yamaha VStar 1300 2007 (wife's) for relaxing

    Comment


      #3
      Please check the Newbie Mistakes thread link in my signature. It will help you.
      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


        #4
        Can't let these things sit on prime, it's asking for trouble. Sort the petcock and the success rate with rebuild kits is low.
        Was it on the centre stand or sidestand? Occasionally mine will leak on prime on sidestand.
        Check your oil level and smell it for gas, although everything probably smells of gas right now.
        Don't run it with gas in there.
        Don't order anything until you have a look at the floats and needles.
        97 R1100R
        Previous
        80 GS850G, 79 Z400B, 85 R100RT, 80 Z650D, 76 CB200

        Comment


          #5
          Originally posted by Nessism View Post
          Please check the Newbie Mistakes thread link in my signature. It will help you.
          Well thanks a lot, I think I've read it all.
          ------ Current rides: -----------------

          Honda CT70 K0 1970 complete restoration in progress
          Suzuki GS850 1979 as stock as could be... well except for the bars!
          Yamaha FJ-09 2016 with OEM saddle bags for long distance running and gunning
          Yamaha VStar 1300 2007 (wife's) for relaxing

          Comment


            #6
            I know, I'm not letting it stand on prime, it's just to have the bike running. I'm shuting off the petcock as soon as I shut the motor.

            No gas in the motor, oil level is fine.

            The leak is while it was on either stand... makes no diff.
            ------ Current rides: -----------------

            Honda CT70 K0 1970 complete restoration in progress
            Suzuki GS850 1979 as stock as could be... well except for the bars!
            Yamaha FJ-09 2016 with OEM saddle bags for long distance running and gunning
            Yamaha VStar 1300 2007 (wife's) for relaxing

            Comment


              #7
              Please, don't tell us what model bike or carbs you have
              Wild speculation is for Facebook

              Put your year and model in your signature, so we're not completely clueless
              1978 GS 1000 (since new)
              1979 GS 1000 (The Fridge, superbike replica project)
              1978 GS 1000 (parts)
              1981 GS 850 (anyone want a project?)
              1981 GPZ 550 (backroad screamer)
              1970 450 Mk IIID (THUMP!)
              2007 DRz 400S
              1999 ATK 490ES
              1994 DR 350SES

              Comment


                #8
                A fairly common source of leaks to look out for are the "fuel rail" pieces that go between the carbs. Between 2&3 is the fuel "T" and between 1&2 and 3&4 are straight connectors with O-rings. Any of these linkages can leak, especially if the O-Rings between 1&2 and 3&4 are original. They come with the O-Ring kits recommended to rebuild GS carbs at cycleorings.com.
                1980/1981 GS450 - GS500 Cylinder + Piston Swap - "De-L'ed", custom seat, CB350 bits, 18" rear, etc.
                1977 GS550
                1977 GS750 - Cross country trip thread

                Comment


                  #9
                  Originally posted by Big T View Post
                  Please, don't tell us what model bike or carbs you have
                  Wild speculation is for Facebook

                  Put your year and model in your signature, so we're not completely clueless
                  Oupsie sorry!

                  GS850 1979 --> carbs are VM

                  I'm fixing this signature right now...
                  ------ Current rides: -----------------

                  Honda CT70 K0 1970 complete restoration in progress
                  Suzuki GS850 1979 as stock as could be... well except for the bars!
                  Yamaha FJ-09 2016 with OEM saddle bags for long distance running and gunning
                  Yamaha VStar 1300 2007 (wife's) for relaxing

                  Comment


                    #10
                    Originally posted by sam000lee View Post
                    A fairly common source of leaks to look out for are the "fuel rail" pieces that go between the carbs.
                    Well, I did put see through plastic lines on the bowl overflow and I can see it's leaking through these. I guess a fuel rail leak wouldn't leak from inside the bowl but would spilled over directly on the crankcase... right?
                    ------ Current rides: -----------------

                    Honda CT70 K0 1970 complete restoration in progress
                    Suzuki GS850 1979 as stock as could be... well except for the bars!
                    Yamaha FJ-09 2016 with OEM saddle bags for long distance running and gunning
                    Yamaha VStar 1300 2007 (wife's) for relaxing

                    Comment


                      #11
                      Originally posted by maisf View Post
                      Well, I did put see through plastic lines on the bowl overflow and I can see it's leaking through these. I guess a fuel rail leak wouldn't leak from inside the bowl but would spilled over directly on the crankcase... right?
                      Try tapping the float bowls with the handle of a screwdriver. Sometimes the floats can get stuck and cause an overflow.
                      Bikes:

                      1980 GS1000 restomod
                      2006 GSXR 750

                      Comment


                        #12
                        You could also try opening the drain screw and let the fuel run through at full chat for a few seconds. With the floats fully down a big piece of grit has a better chance to clear the float needle. Which carb(s) is it?
                        97 R1100R
                        Previous
                        80 GS850G, 79 Z400B, 85 R100RT, 80 Z650D, 76 CB200

                        Comment


                          #13
                          Originally posted by Brendan W View Post
                          Which carb(s) is it?
                          I guess it's the third one as it's feeding the cylinder #3...

                          80GS1000 : I'll try this! The more I think about it the more it make sense that the float is getting stock down low. A needle problem would be more likely a slow leak I guess... Unless some grit got stock like Brendan suggested...

                          Both are good ideas! I'm trying them now!

                          Thanks guys!
                          ------ Current rides: -----------------

                          Honda CT70 K0 1970 complete restoration in progress
                          Suzuki GS850 1979 as stock as could be... well except for the bars!
                          Yamaha FJ-09 2016 with OEM saddle bags for long distance running and gunning
                          Yamaha VStar 1300 2007 (wife's) for relaxing

                          Comment


                            #14
                            Well, tapping the bowl didn't show any improvements.

                            But..... Opening the drain screw on the offending carb did make the problem disapear!

                            At least for a few kms. The leak got back as worse as ever and I made a donation of 4 or 5 liters of gas to the speed gods getting back home.

                            I guess I'll be tearing this apart this weekend.
                            ------ Current rides: -----------------

                            Honda CT70 K0 1970 complete restoration in progress
                            Suzuki GS850 1979 as stock as could be... well except for the bars!
                            Yamaha FJ-09 2016 with OEM saddle bags for long distance running and gunning
                            Yamaha VStar 1300 2007 (wife's) for relaxing

                            Comment


                              #15
                              I called my local Suzuki dealer yesterday, saying to myself, what the heck just change all these float needles and all will be good...

                              Gulp... That's 254 CAN$. It's quite a bit steeper than I thought...

                              I read someone talking about getting those from Amazon at 15 bucks a piece but I couldn't find them as of now.

                              From your experiences, would it make any sense to just replace the faulty one?
                              ------ Current rides: -----------------

                              Honda CT70 K0 1970 complete restoration in progress
                              Suzuki GS850 1979 as stock as could be... well except for the bars!
                              Yamaha FJ-09 2016 with OEM saddle bags for long distance running and gunning
                              Yamaha VStar 1300 2007 (wife's) for relaxing

                              Comment

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