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Carbs, carbs, what the heck is wrong with these carbs

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  • #16
    Carb Floats

    Hi Rob. This may be applicable.Seems you looked at everything else.When I was working on one of my spare sets of 79's, I switched out the brass for the foam ones. Found that the float bottomed out and stuck on one side on the passage that runs diagonally across the bottom of the carb body. Probably the pilot, can't remember off hand. Anyway I wound up having to shave a bit off the curved portion and make sure the float was centerd between the posts to get a smooth action. I've bought a couple sets of foam floats now and some had the sleeve for centering and some didn't. If that is the carb body I sent you and it's screwed, I have another here you can try. You know. To zero in on this issue you may have to split the carbs again and check them all individually.
    mack
    79 XS 1100 SF Special
    HERMES
    original owner
    http://i946.photobucket.com/albums/a...ps6932d5df.jpg

    81 XS 1100 LH MNS
    SPICA
    http://i946.photobucket.com/albums/ad305/mack-055/2.jpg

    78 XS 11E
    IOTA
    https://youtu.be/wB5Jfbp6SUc
    https://youtu.be/RaI3WYHSuWA



    Have recovery trailer and shop if you breakdown in my area.
    Frankford, Ont, Canada
    613-398-6186

    Comment


    • #17
      Originally posted by mack View Post
      Hi Rob. This may be applicable.Seems you looked at everything else.When I was working on one of my spare sets of 79's, I switched out the brass for the foam ones. Found that the float bottomed out and stuck on one side on the passage that runs diagonally across the bottom of the carb body. Probably the pilot, can't remember off hand. Anyway I wound up having to shave a bit off the curved portion and make sure the float was centerd between the posts to get a smooth action. I've bought a couple sets of foam floats now and some had the sleeve for centering and some didn't. If that is the carb body I sent you and it's screwed, I have another here you can try. You know. To zero in on this issue you may have to split the carbs again and check them all individually.
      I appreciate that Mack but I really don't think its the body. The foam floats that are in them are the same ones that worked fine for those previous years but i will check that. I think I'm just going to have to bit the bullet and do a FULL cleaning again like I did some 4 years ago when I first got this bike. That being the case, this season does appear to be toast for me and I only managed to put perhaps 150 KMs on her. This lack of daily use may also be a problem. I have just been so busy with work and other around the house jobs that time flys.
      Rob
      KEEP THE RUBBER SIDE DOWN

      1978 XS1100E Modified
      1978 XS500E
      1979 XS1100F Restored
      1980 XS1100 SG
      1981 Suzuki GS1100
      1983 Suzuki GS750S Katana
      1983 Honda CB900 Custom

      Comment


      • #18
        I have been thinking about this issue for several days as well as while I was working on the carbs trying to fix the issue. It occurs to me that the only thing I did differently this spring was to dose the gas supply with SeaFoam. I have put sea foam through the fuel system in the past during the biking season but never before have I added it to the first tank of the year. This makes me wonder if there's a connection between this and the issue I'm having. I wonder if that treatment freed up some crap in the carbs that has built up over 3 years and the issue is as simple as dirty carbs. It's the last and only conclusion I can come to at this point.
        Rob
        KEEP THE RUBBER SIDE DOWN

        1978 XS1100E Modified
        1978 XS500E
        1979 XS1100F Restored
        1980 XS1100 SG
        1981 Suzuki GS1100
        1983 Suzuki GS750S Katana
        1983 Honda CB900 Custom

        Comment


        • #19
          Hi Rob,

          I would highly suspect the lack of daily use. I chased the same issue and was ready to toss everything when I realized that the flooding problems went away with daily riding. If I let the girl sit for a few weeks, I would start to have flooding issues all over again.

          Ernie
          Ernie
          79XS1100SF (no longer naked, now a bagger)
          (Improving with age, the bike that is)

          Comment


          • #20
            Originally posted by egsols View Post
            Hi Rob,

            I would highly suspect the lack of daily use. I chased the same issue and was ready to toss everything when I realized that the flooding problems went away with daily riding. If I let the girl sit for a few weeks, I would start to have flooding issues all over again.

            Ernie
            I could accept that as the cause but it really should not be the case. My fuel petcocks are new OEM units that don't leak a drop. The carbs, if cleaned properly and outfitted with new jets etc should function like close to new. When these bikes were new and for several years after did not have to be used daily to keep them running well.
            Rob
            KEEP THE RUBBER SIDE DOWN

            1978 XS1100E Modified
            1978 XS500E
            1979 XS1100F Restored
            1980 XS1100 SG
            1981 Suzuki GS1100
            1983 Suzuki GS750S Katana
            1983 Honda CB900 Custom

            Comment


            • #21
              When these bikes were new and for several years after did not have to be used daily to keep them running well./////
              Very true 79XS. /when new living where snow stopped the riding for 4-5months would just put it in the storage shead and remove the battery. Long bout April, drag it out, put in the battery, crank it and away it would go. Now with a real man-cave, don't do that and ride on and off all winter here. Both the XS and ST have been known to sit for a couple months without riding on and off for several years and have no running issues, so me thinks the issue your having can't be attributed to lack of daily riding.
              81H Venturer1100 "The Bentley" (on steroids) 97 Yamaha YZ250(age reducer) 92 Honda ST1100 "Twisty"(touring rocket) Age is relative to the number of seconds counted 'airing' out an 85ft. table-top.

              Comment


              • #22
                Originally posted by 79XS11F View Post
                I could accept that as the cause but it really should not be the case. My fuel petcocks are new OEM units that don't leak a drop. The carbs, if cleaned properly and outfitted with new jets etc should function like close to new. When these bikes were new and for several years after did not have to be used daily to keep them running well.
                Rob
                They didn't have parts from other bikes in them either. JAT
                Greg

                Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.”

                ― Albert Einstein

                80 SG Ol' Okie;79 engine & carbs w/pods, 45 pilots, 140 mains, Custom Mac 4 into 2 exhaust, ACCT,XS850 final drive,110/90/19 front tire,TKat fork brace, XS750 140 MPH speedometer, Vetter IV fairing, aftermarket hard bags and trunk, LG high back seat, XJ rear shocks.

                The list changes.

                Comment


                • #23
                  Gas formulas were very different back when these bikes were new as well. I didn't have an XS11 by had my XS400 back then, and it could easily sit for 3 to 4 weeks at a time with no problems with the carbs at all, just fire it up and go. But these days, if you try that, you WILL have gummed up carbs. Modern gas CANNOT be allowed to sit in the fuel system without some sort of stabilization, and I'm not sure seafoam will work well enough, even though it claims it will, but I've had good luck with most stuff with stabil, but it didn't do well in my XS400, after just 6 months the carbs now need to be cleaned (it claims to keep it stable longer than that) and the gas won't work in anything, not even my lawnmower.

                  I'm to the thing of if I'm going to let a bike sit, drain the tank and carbs, coat the inside of the tank with a light coat of oil to protect from rust and leave things dry. Less chance of problems and then when putting back in service is always fresh gas, no gum or varnish that way. That's why I asked about the vents, cause I'd be concerned about the vents getting clogged by bad gas, if there is any ethanol in it, it will turn to jelly, which won't let air through.
                  Cy

                  1980 XS1100G (Brutus) w/81H Engine
                  Duplicolor Mirage Paint Job (Purple/Green)
                  Vetter Windjammer IV
                  Vetter hard bags & Trunk
                  OEM Luggage Rack
                  Jardine Spaghetti 4-2 exhaust system
                  Spade Fuse Box
                  Turn Signal Auto Cancel Mod
                  750 FD Mod
                  TC Spin on Oil Filter Adapter (temp removed)
                  XJ1100 Front Footpegs
                  XJ1100 Shocks

                  I was always taught to respect my elders, but it keeps getting harder to find one.

                  Comment


                  • #24
                    I would have to agree with modern gas contributing to problems. I know in my case everything worked fine until I parked the bike for a while. If the unknown in the equation is time, I would be led to believe the culprit is fuel breakdown. Adding credibility to this theory is a recent problem I ran into with a friends restored Cougar. Brand new carb on a rebuilt 5 litre started to flood out on the way back from a local car show. After tearing down the carb he discovered it was already gummed up from less then one month old fuel.

                    Our carbs are quite simple in their operation but as we all know, are very sensitive to contaminants.

                    I never had any of these issues in the eighties or even nineties (mid) The only change from then to now I can think off is fuel.
                    Ernie
                    79XS1100SF (no longer naked, now a bagger)
                    (Improving with age, the bike that is)

                    Comment


                    • #25
                      Modern fuel likely is playing a roll in this situation. I typically drain my fuel tank and drain my carbs as well for the winter storage period. I must wonder if every drop of fuel is getting out of all the galleries even when the carbs are drained using the bottom drain on the carb bowls. If any fuel is left behind it would evaporate pretty quick and leave behind its deposits. This is what I think has likely happened. I was goiing to store the bike "wet" this year to avoid this potenial issue but it will likey prove to be better to drain the carbs as usual and then blow them out with air at low pressure by way of the vent hoses. Ether that or take the carbs off every winter for DRY storage.
                      Rob
                      KEEP THE RUBBER SIDE DOWN

                      1978 XS1100E Modified
                      1978 XS500E
                      1979 XS1100F Restored
                      1980 XS1100 SG
                      1981 Suzuki GS1100
                      1983 Suzuki GS750S Katana
                      1983 Honda CB900 Custom

                      Comment


                      • #26
                        one word

                        stabalizer. Put stabalizer in the tank, then take it for a ten mile ride before I put him up for the winter. Every month I'll back him up to the shop door and run him for about five minutes, working the clutch and rolling through various RPM ranges(I have two vary large box fans running over the motor). No issues with rust in tank or gas turning to shelack. He starts everytime with one button push. 3 phase gave me the best tip so I'll pass it on. Ditch the viton tip needles and valves on your 79 carbs and go back to new originals.
                        mack
                        79 XS 1100 SF Special
                        HERMES
                        original owner
                        http://i946.photobucket.com/albums/a...ps6932d5df.jpg

                        81 XS 1100 LH MNS
                        SPICA
                        http://i946.photobucket.com/albums/ad305/mack-055/2.jpg

                        78 XS 11E
                        IOTA
                        https://youtu.be/wB5Jfbp6SUc
                        https://youtu.be/RaI3WYHSuWA



                        Have recovery trailer and shop if you breakdown in my area.
                        Frankford, Ont, Canada
                        613-398-6186

                        Comment


                        • #27
                          Hey Mack,

                          Where did you get good original valves and seats. IIRC the last set I got were crap. I looked at them through a magnifying glass and the machining looked pretty rough, couldn't even get a good seal on a bench test. I recall getting some parts through a dealer, thinking they were NOS only to discover the parts we actually aftermarket cheapos at OEM prices.

                          Ernie
                          Ernie
                          79XS1100SF (no longer naked, now a bagger)
                          (Improving with age, the bike that is)

                          Comment


                          • #28
                            NEEDLE VALVE SET (25G-14107-20-00) $16.94 $14.63

                            http://www.yamahasportscenter.com/fi...5G-14107-20-00
                            Marty (in Mississippi)
                            XS1100SG
                            XS650SK
                            XS650SH
                            XS650G
                            XS6502F
                            XS650E

                            Comment


                            • #29
                              Originally posted by egsols View Post
                              Hey Mack,

                              Where did you get good original valves and seats. IIRC the last set I got were crap. I looked at them through a magnifying glass and the machining looked pretty rough, couldn't even get a good seal on a bench test. I recall getting some parts through a dealer, thinking they were NOS only to discover the parts we actually aftermarket cheapos at OEM prices.

                              Ernie
                              You can still get them through the dealers but I got lucky and got mine on eBay along with 4 main jets, 4 needles and 4 pilots jets. Everything came in sealed Yamaha packaging and I got it all for 39 bucks.
                              Rob
                              KEEP THE RUBBER SIDE DOWN

                              1978 XS1100E Modified
                              1978 XS500E
                              1979 XS1100F Restored
                              1980 XS1100 SG
                              1981 Suzuki GS1100
                              1983 Suzuki GS750S Katana
                              1983 Honda CB900 Custom

                              Comment


                              • #30
                                seats and needles

                                Sorry been having computor issues. Seems Mcafee took over on it's own and firewalled me from the internet. However I'm in charge again.
                                Think I got mine from Parts more. I was having the same issues as Rob and 3 phase recommended I go back to the originals. Worked like a charm. None of the 79 carb banks leak at all, and I must confess, I have forgotten to turn off the fuel petcocks a few times (removed the octy) and they haven't leaked. I also use the brass floats.
                                Now in the 81 carbs, I'm not at the reassembly stage yet, they're all clean and have the foam floats(which I hate) but I'm still dealing with paint and plating and cleaning up the wireing harness right now. Once the winter wood is in, I should have all the stuff back and will start the assembly process. I like to do the carbs last, but will dial in all three sets at the same time.
                                mack
                                79 XS 1100 SF Special
                                HERMES
                                original owner
                                http://i946.photobucket.com/albums/a...ps6932d5df.jpg

                                81 XS 1100 LH MNS
                                SPICA
                                http://i946.photobucket.com/albums/ad305/mack-055/2.jpg

                                78 XS 11E
                                IOTA
                                https://youtu.be/wB5Jfbp6SUc
                                https://youtu.be/RaI3WYHSuWA



                                Have recovery trailer and shop if you breakdown in my area.
                                Frankford, Ont, Canada
                                613-398-6186

                                Comment

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