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  • #1

    YICS Virgin

    My friend's XJ650 project is giving us fits. We have been in the carbs a bunch of times and they are clean with the float levels set correctly. We used the bread tie method to start and then constructed the a YICS tool as per the instructions I found on the web. I suspect its not sealing because I can't get the balance and hence the rising idle problem. Right now we cant get it to idle at all below about 2000. Would any one have a known working YICS that they would be willing to lend? I'm thing of removing the rack and setting the sync with the fine wire one more time. Any idea would help

    Thanks
    Dave
    wingnut
    81 SH (Daily Ride)
    81 650XJ (Brother in laws bike, Delivered)
    81 650XJ Jane Doe (Son's Ride)
    82 750XJ Project bike (Son in law's future ride)
    81 XS 400

    No man has a natural right to commit aggression on the equal rights of another; and this is all from which the laws ought to restrain him.”

    A government big enough to give you everything you want, is strong enough to take everything you have.

    Thomas Jefferson
    Tags: None
  • #2
    yics

    I've worked on the 1100 yics system with a new tool that one of our members (Yahman) has invented and is far superior to the conventional yics tools.

    http://www.xs11.com/forum/showthread...399#post183399

    If your XJ650 is 4cyl, this tool will work. After syncing, just leave it in the passage permanently.
    2H7 (79)
    3H3

    "If it ain't broke, modify it"

    ☮

    Comment

    • #3
      Well we went back to squire one and it all worked out well. Removed the rack and reset the sync using a very fine wire. We also removed the carb boots from the engine and fabricated gaskets. These boots had been replaced and just permatexed on by the PO. Lots of leak paths could be seen. Reassembled and installed a modified YICS tool which used rubber tubes with slightly larger outer diameter. First start was very nice and the mercury was halfway up the tubes virus very near the bottom on the previous runs. Synced up with very little adjustment. Throttle response was in the right now category. Checked the idle mixtures with the color tune and they looked good. All 4 are set at right around 3 turns out. We pulled a compression check and cold dry gave us reading of 135 or there abouts. So its all back together now and on the streets. Another ebay special saved from the scrap yard.
      wingnut
      81 SH (Daily Ride)
      81 650XJ (Brother in laws bike, Delivered)
      81 650XJ Jane Doe (Son's Ride)
      82 750XJ Project bike (Son in law's future ride)
      81 XS 400

      No man has a natural right to commit aggression on the equal rights of another; and this is all from which the laws ought to restrain him.”

      A government big enough to give you everything you want, is strong enough to take everything you have.

      Thomas Jefferson

      Comment

      • #4
        Okay, i give up, although i know yall are gonna laugh at my youth and inexperience but what the hell is a "YICS"? I've heard that term alot in the past couple days on this site and have yet to learn what it stood for (if it were an acronym) or if it's an actual part on the bike called a yics? Anyways can someone please fill me in on this one?
        Yes it's a damn nice bike, yes it's in REALLY good condition, yes it would be a shame to chop it, BUT damn how cool would it look with ape hangers?

        Comment

        • #5
          Yics

          HI Bowtied,
          As the proud owner of a YICS equiped Yamaha
          The way I understand it is a wonderful gizmo with no moving parts
          Simply put ( why would i complicate it you are already confused)
          By having a small passage ( hole ) between the carburretors the synchronization of the carbs is less critical.
          My interpretation ( I have been wrong before, married once)is:
          Yamaha Induction Compensation System.
          Guru's and others more informed can jump in any time
          Phil
          1981 XS1100 H Venturer ( Addie)
          1983 XJ 650 Maxim
          2004 Kawasaki Concours. ( Black Bear)

          Comment

          • #6
            Close Phil.

            Yamaha Induction Control System.

            The YICS is an additional tube attached to the back of the cylinders that match up with a like tube in the head of motors with YICS.



            And here's where the holes in the cylinder YICS tube match up with the holes in the head.




            A head WITH YICS (Top) and one without..





            Up inside these holes in the head....




            There are orifices at the top that lead to the intake chamber dirctly in front of the intake valve.





            So basically what the YICS does is tie and equalize all the carbs together. As the piston draws in an air/fuel mix from it's appointed carb, it is also drawing some from this YICS tube wich connects all the other intake ports and carb mixes. It was done for the California Emissions that were getting more stringent when the XJ came along. A bike without YICS that had a single out of synch carb would likely fail a smog test. With the YICS, the bad carb would get equalized out by the other three somewhat and help it stay in smog spec limits longer. The poorly performing single carb would be divided amongst all four cylinders this way, making it not as bad.

            SO.. When it comes time to synchronize the carbs on a bike with YICS, you have to install a tool that seals this tube in between each of the carbs so you are individualizing each carb and would then be able to synchronize it. Without the YICS tool, all the carbs SHOULD have the same reading on a synch gauge and you wouldn't know which carb was the bad one.


            Did this help.. or did I just confuse you more? lol.

            Tod
            Last edited by trbig; 12-31-2008, 10:14 PM.
            Try your hardest to be the kind of person your dog thinks you are.

            You can live to be 100, as long as you give up everything that would make you want to live to be 100!

            Current bikes:
            '06 Suzuki DR650
            *'82 XJ1100 with the 1179 kit. "Mad Maxim"
            '82 XJ1100 Completely stock fixer-upper
            '82 XJ1100 Bagger fixer-upper
            '82 XJ1100 Motor/frame and lots of boxes of parts
            '82 XJ1100 Parts bike
            '81 XS1100 Special
            '81 YZ250
            '80 XS850 Special
            '80 XR100
            *Crashed/Totalled, still own

            Comment

            • #7
              Originally posted by trbig View Post
              Close Phil.

              Yamaha Induction Control System.

              The YICS is an additional tube attached to the back of the cylinders that match up with a like tube in the head of motors with YICS.



              And here's where the holes in the cylinder YICS tube match up with the holes in the head.




              A head WITH YICS (Top) and one without..





              Up inside these holes in the head....




              There are orifices at the top that lead to the intake chamber dirctly in front of the intake valve.





              So basically what the YICS does is tie and equalize all the carbs together. As the piston draws in an air/fuel mix from it's appointed carb, it is also drawing some from this YICS tube wich connects all the other intake ports and carb mixes. It was done for the California Emissions that were getting more stringent when the XJ came along. A bike without YICS that had a single out of synch carb would likely fail a smog test. With the YICS, the bad carb would get equalized out by the other three somewhat and help it stay in smog spec limits longer. The poorly performing single carb would be divided amongst all four cylinders this way, making it not as bad.

              SO.. When it comes time to synchronize the carbs on a bike with YICS, you have to install a tool that seals this tube in between each of the carbs so you are individualizing each carb and would then be able to synchronize it. Without the YICS tool, all the carbs SHOULD have the same reading on a synch gauge and you wouldn't know which carb was the bad one.


              Did this help.. or did I just confuse you more? lol.

              Tod
              Thanks Tod,
              Less confused but at a much higher level
              However this is much clearer than Electricity which is still PFM to me
              Phil
              PFM = Pure ****ing Magic
              1981 XS1100 H Venturer ( Addie)
              1983 XJ 650 Maxim
              2004 Kawasaki Concours. ( Black Bear)

              Comment

              • #8
                It cleared it up quite a bit actually! I assumed it had a alittle something to do with the carb's seeing as how everyone tosses around the "yics" word when talken about synchronizing the carbs and what not. So yeah it did help a bunch! THanks guys!
                Yes it's a damn nice bike, yes it's in REALLY good condition, yes it would be a shame to chop it, BUT damn how cool would it look with ape hangers?

                Comment

                • #9
                  Has anyone checked the sync of the carbs
                  with and without the yics tool to see if the tool
                  actually makes a difference.
                  in theory with the yics system set up after the sync
                  guages, wouldnt a correct reading be obtained without
                  the use of a yics tool.
                  pete


                  new owner of
                  08 gen2 hayabusa


                  former owner
                  1981 xs1100 RH (aus) (5N5)
                  zrx carbs
                  18mm float height
                  145 main jets
                  38 pilots
                  slide needle shimmed .5mm washer
                  fitted with v/stax and uni pod filters

                  [url]http://www.youtube.com/watch?v=3pA8dwxmAVA&feature=mfu_in_order&list=UL[/url]

                  Comment

                  • #10
                    yics

                    Without the tool installed, all the vac gauges will read the same. Turning the sync screws doesn't change the readings, so you'll never know if the carbs are equal. After installing the tool, the readings will be different from each other and the sync screws will change the readings just like a normal non yics setup. The idea is to have all carbs equal with the yics passage blocked so all cylinders are pulling the same. Then remove the tool and you're done. If you have member Yahman's yics tool, you can leave the tool in the passage permanently and the engine will behave just like a regular XS setup. I've used this tool and highly recommend it. Yics power is just a cover up for pollution control system. HTH
                    2H7 (79)
                    3H3

                    "If it ain't broke, modify it"

                    ☮

                    Comment

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