Announcement

Collapse
No announcement yet.

Please help!!!

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Please help!!!

    OK long story short. i have rebuilt the engine, this was two years ago, i have been riding it with no problems for those two years, i have oned the bike for 9-10 years, been riding it for 9 years. i did not burn out the carbs last year and this year it only runs on the two right cylinders. i just took the carbs completly apart as i have done several times befor, i did not find anything inside as far as dirt or anything that should not be in there. but my floats were off and my needle valves had groves in them, so i replaced the needles and adjusted the floats to 25.7mm, main jet 138, pilot jet is 180, small jet is 42.5, MAC exaust 4-2, and pod air filters, accell coils (yellow) as i said i road it for two years like this with no problem. so now what it is doing is with the tank off and small fuel containers going directly to the fuel in on the carbs, it burns fuel faster on the right, if i pull one or both left plug wires makes no difference, so switched the wires 1-4 and 2-3 because it has waste spark and its the same thing, so i tried to pull the wires off of both right cyinders and tried to start it. it starts and runs on both left cylinders but not as powerfull as the right 2 cylinders, but it does run. i know the carbs are clean, i blew shop air through all pasages in all carbs and all passages had the same amount of air comming out of the on all carbs, so i really dont think it is a glogged carb, it does not make sence that is in the ignition system because i used both sides of both coils on all cylinders and it made no difference, my pick- up coils are not original i have replaced them. when you try to rev it with everything hooked up it sounds like it is just sucking alot of air and it boggs down, if i keep on and off the throttle over and over and i get it up to 3000 rpm then it runs fine.
    any input would be greatly appreciated.
    Thanks
    Troy
    79' XS1100SF

  • #2
    Just checked my pick up coils 810 ohms and 809 ohms limit in the yamaha service manual says 720 +- 20%. 20%=144
    79' XS1100SF

    Comment


    • #3
      Just to see I put the original Ignition coils back on (not pick up coils) and it still does the same thing so as far as I can tell it's a carb problem.
      79' XS1100SF

      Comment


      • #4
        Did you remove the low circuit jets and clean them out? They are the ones in the float bowl under a flat headed screw. Did you clean the emulsion tubes? If the bike sat, the tiny holes in these parts can/will clog up. Only way is to remove them from the carbs and clean them AND their passages out with carb cleaner spray.
        2H7 (79) owned since '89
        3H3 owned since '06

        "If it ain't broke, modify it"

        ☮

        Comment


        • #5
          yes i did remove those small jets and the imusification tubes, they are clean, it just does not make sence, i am almost positive its in the carbs though, just dont know what, its almost as if both left carbs are not letting enough fuel into the cylinder or not atomizing it enough. after i put the old coils back on it back fires really bad on the left tail pipe. thanks for the thought though
          79' XS1100SF

          Comment


          • #6
            Ok, another thought. Check the idle mixture screws and make sure the tips aren't broken off and stuck in the carb throat. They are very prone to breaking on the early type carbs that you have.
            2H7 (79) owned since '89
            3H3 owned since '06

            "If it ain't broke, modify it"

            ☮

            Comment


            • #7
              Check gas lines for kinks and the rest of the fuel delivery system for plug ups.
              '81 1100 MNS - "Midnight XSpress"
              Original except:
              120 mains outer cylinders - 125 mains inner cylinders - Ceramic headers - Powder coated pipes, covers calipers, and MC's
              4 pods - Air box gutted--E3 Plugs - High Back seat - Grooved out swing arm - SS brake lines
              Fork brace - 160 speedo - Auto CCT
              All gold paint and chrome replaced with GOLD plate

              "STUPID is Forever" Ron White.
              Contact me by PM -I don't deal with stupid anymore.

              Big John

              Comment


              • #8
                Originally posted by jmnjrpa View Post
                Check gas lines for kinks and the rest of the fuel delivery system for plug ups.
                +1


                Since both carbs on that side are having problems it stands to reason it may have something to do with the one line or petcock that feeds both carbs.I have had the kinked line thing bite me a couple of times.
                Do you have clear fuel lines?If so, are they full of fuel?And do they remain full while running?
                80 SG XS1100
                14 Victory Cross Country

                Comment


                • #9
                  its not the fuel lines, i am using two rather large syringes that go to two brand new fuel lines that are straight. and its not broken off mixture screws, i have already goten the broken ones out years ago. two years ago when i rebuilt the engine, i got a used set of carbs from someone here at XS11.com
                  because on my #2 carb, one of the float mounts broke off, and i tried to fix it but nothing worked. today i am going to try to put the other #1 carb i have on and see if #1 comes back to life. i don't know if i can make #4 work for #2or not. i have to check it out, i might be in the market for some carbs if anyone has a set they want to sell. thanks for all of your advice, more is always welcome.
                  Thanks
                  Troy
                  79' XS1100SF

                  Comment


                  • #10
                    Sounds to me like all you have done 2 years ago was great, and worked. Don't discount the fact that you may need to go through some of those things again. IE carbs. Another thing, you need to pull on the pickup wires while measuring them. They can/will read through when cold, and not moving. Advance them by hand as well and read them. I didn't see where you said how or if you checked for spark at the plugs. Go to the basics first. Fuel, air, compression, electrical connections, etc.
                    1980 XS1100LG Midnight
                    1991 Honda CBR1000F Hurricane


                    "The hand is almost valueless at one end of the arm if there be not a brain at the other"

                    Here's to a long life and a happy one.
                    A quick death and an easy one.
                    A pretty girl and an honest one.
                    A cold beer and another one!

                    Comment


                    • #11
                      I know what you saying about the pick up coils but it does not make sence that it would be them because one pick up coil operates one ignition coil and # 3 and 4 are on different coils and they (3 and 4) work fine. I do have spark and I had said in a previos response that I can get the bike to run on cyliners 1 and 2 only but 3 and 4 run a whole lot better and when it is running with all 4 hooked up and I pull 1 or 2 plug wire it makes no difference. I agree the next thing to check is compression but I don't think that is it because the chances of two cylinders loosing compresion at the same time is unlikely unless my head gasket is blown. I have the carbs off right now and I took #1 completly apart and I can't see anything that is wrong. I am blowing compressed air through all the holes and getting it to come out of another. I can't use #4 carb for #2 because the vacume port for the advance is not there
                      Last edited by raqumup; 05-31-2010, 09:04 AM.
                      79' XS1100SF

                      Comment


                      • #12
                        IS the orifice in the bottom of the float bowl clear?
                        80 SG XS1100
                        14 Victory Cross Country

                        Comment


                        • #13
                          sounds like its firing on all four cylinders,
                          the only thing i could think of would be a carb sync,
                          the left and right banks are out of sync, jat.
                          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


                          • #14
                            Yes that small hole in the carb bowls are clear. Just did a compression test
                            180 180 155 175 and I did a leakdown test
                            5% 5% 5% 3-4%. Keep in mind that the problem ones are the 180 and 180. As far as I can tell the spec is 142 with a max difference of 14. I know I am outside the difference but the one that is out works just fine. I am going to try to sync them I have the mercury tubes. I don't think that is it because I don't see how the can get out of sync from just sitting for 5-6 months but we shall see. Thanks for all the help guys I really appreciate it
                            Troy
                            79' XS1100SF

                            Comment


                            • #15
                              Does anyone know what passage the three small holes go to that are right at the top of the throtle plate. They are right befor the throtle plate in line with the mixture screw?
                              79' XS1100SF

                              Comment

                              Working...
                              X