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79 xs1100 special... jetting question (pod filters no baffles)

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  • 79 xs1100 special... jetting question (pod filters no baffles)

    Hi! I bought a factory exhaust for my xs1100 off a buddy of mine, it is the dual setup. The muffler baffles are completely out and I also got his almost new pod filters.

    This was his dads bike and sat for many years without running so I cant just use his carbs. My bike is in excellent running condition just had a rusted out 4-1 exhaust on it.

    I just need to know what jets I should use and where I can get them in order to make the pod filters and exhaust work properly.

  • #2
    Hey there Itbparada,

    We're not trying to "Diss" you, but you would be amazed at the volume of information you can find by reviewing the Tech Tips, Misc, and the LINKs section. There is a jetting guide. Several places to get jets, BikeBandit, MikesXS.

    SO, we highly recommend reading thru the tech tips, and THEN, if you still can't quite figure it out, ask away, and we'll be more than happy to give you our insights into your situation!!
    T.C.
    T. C. Gresham
    81SH "Godzilla" . . .1179cc super-rat.
    79SF "The Teacher" . . .basket case!
    History shows again and again,
    How nature points out the folly of men!

    Comment


    • #3
      thanks...

      Only problem is that all of the web surfing I do is on my cell phone (I'm not a computer guy) so it is very hard 2 surf pages let alone try and find something.

      A buddy of mine said to post on here, that u guys knew what u were doing on this forum and would help me out.

      Any help is greatly appreciated... Thanks!

      Comment


      • #4
        Jetting Guide info!

        Sorry,

        Didn't know you were computer challenged!!

        Here's a quote from the guide!
        Jetting Recommendations
        by Denny Zander

        Here is a simple set of jetting guidelines that have worked for me. For those considering jet changes, this might help select a starting point.

        1 jet size for custom 4 into 2 exhaust

        2 jet sizes for 4 into 1 exhaust

        1 jet size for K&N filter (single inside airbox)

        1 jet size for drilling out the bottom of the airbox

        3 jet sizes for individual filters

        2 jet sizes for no muffler (open header)

        1 pilot jet size for every 3 main jet size increase

        Add up all the jet size increases and subtract one. (Remember they go in steps of 2.5 for each jet size)
        So..it seems like you would want about 4 sizes up from stock!?
        Stock 137.5, so going up to 147.5 is what the guide states!
        BikeBandit.com is a good place for the jets, but you would be better off shopping for them with a full size computer!

        Or, you could just go to your local Yamaha Dealer, and get them there as well!? Good Luck!
        T.C.
        T. C. Gresham
        81SH "Godzilla" . . .1179cc super-rat.
        79SF "The Teacher" . . .basket case!
        History shows again and again,
        How nature points out the folly of men!

        Comment


        • #5
          TopCatGr58 bless u for the tldr. Questions about the slide needle.

          79 1100 special. 4-1 i took out the baffle. All 4 carbs have those cheap pods from mikes. Im going to try and follow your guide but should i be adjusting the slide needles? And also. Is jet size important when im just trying to start the bike? Mine is having a hard time running. Spark plugs are black black. Im guessing the mixture is too rich! And i get insane back fire close to gun shots. Thank you.

          Comment


          • #6
            Try running the engine without the cheap pod filters and see if it runs better. The air jets may be restricted by them. You will have to clean your plugs so they fire properly don't forget.

            Top Cat hasn't been around for some time, I hope he responds though.

            The slide needles need to be in the center position.
            Last edited by bikerphil; 04-24-2022, 08:02 PM.
            2H7 (79)
            3H3

            "If it ain't broke, modify it"

            Comment


            • #7
              Originally posted by Snareguy View Post
              TopCatGr58 bless u for the tldr. Questions about the slide needle.

              79 1100 special. 4-1 i took out the baffle. All 4 carbs have those cheap pods from mikes. Im going to try and follow your guide but should i be adjusting the slide needles? And also. Is jet size important when im just trying to start the bike? Mine is having a hard time running. Spark plugs are black black. Im guessing the mixture is too rich! And i get insane back fire close to gun shots. Thank you.
              Did you or the PO rebuild the carbs recently with K&L carb kits? The pilot (slow) jet in those kits is wrong. I had a similar issue caused by the wrong jet in the K&L kit. My bike was so rich it would hardly run. I changed to Mikuni pilot jets and the problem was solved.
              -Mike
              _________
              '79 XS1100SF 20k miles
              '80 XS1100SG 44k miles
              '81 XS1100H Venturer 35k miles
              '79 XS750SF 17k miles
              '85 Honda V65 Magna ~7k miles
              '84 Honda V65 Magna 48k miles (parts bike)
              '86 Yamaha VMAX 9k miles

              Previous: '68 Motoguzzi 600cc + '79 XS750SF 22k miles +'84 Honda V65

              Comment


              • #8
                bikerphil Ill be cleaning those plugs tonight with coke. Next try ill have to pull the carbs back a touch to not cover the air jet. I do notice my air inlet jet will spit back some gas at times. not frequent just occasionally as if its sneezing out into the pod not sure whats happening there. Also i mightve f'd up the butterflys when i was cleaning the carb during disassembly. Do you know what size gap they should be at rest? i heard from an old youtube video all butterflies should be .005 with a feeler gage. Thanks phil! TopCatGr58 Come back to us buddy!

                Radioguylogs As for the rebuild kits from me and PO i am not sure of the brand. my first set was off amazon (tips broke off of course). Second set uninstalled yet but are from ebay. Im going to have to buy some OEM parts to cross reference with the cheap china parts and see if its defective parts or a f'd up carb. The threads on my air/mixture tunnel dont seem to like the aftermarket screws, that or ive fckd up the threads inside. I did a number on the holes from inside the carb trying to push out the stuck tips. If you have a good source where to get nice fitting tips for a 79 special that would be nice! Thanks Radio!

                Comment


                • #9
                  From your response, I'm not sure you realized I was asking about the pilot jets, not the air/fuel mixture screws:

                  https://www.jetsrus.com/a_jets_by_ca...0-96_pilot.htm

                  Regarding the mixture screws, I've had no problem using the screws in the K&L kits.







                  -Mike
                  _________
                  '79 XS1100SF 20k miles
                  '80 XS1100SG 44k miles
                  '81 XS1100H Venturer 35k miles
                  '79 XS750SF 17k miles
                  '85 Honda V65 Magna ~7k miles
                  '84 Honda V65 Magna 48k miles (parts bike)
                  '86 Yamaha VMAX 9k miles

                  Previous: '68 Motoguzzi 600cc + '79 XS750SF 22k miles +'84 Honda V65

                  Comment


                  • #10
                    The gap of the butterfly's should be all the same, they can all be simultaneously opened and closed with the main idle adjustment thumb screw. I guess .005" sounds about right.
                    I use a propane torch to clean fouled plugs.
                    2H7 (79)
                    3H3

                    "If it ain't broke, modify it"

                    Comment


                    • #11
                      Radioguylogs sorry. Misunderstood. Havent had problems with the jet threads or anything with the kits ive gotten. But ill keep an eye out which arent up for the job.

                      Last edited by Snareguy; 04-25-2022, 11:53 PM.

                      Comment


                      • #12
                        bikerphil

                        Going off a previous thread. regarding jets and pods.
                        http://www.xs11.com/forum/showthread.php?t=35932

                        42.5/137.5 is stock

                        if im on pods + 4-1 exhaust + no baffle (open header style?) id have to add 13 sizes bringing me to
                        47.5/150 ? my air jets say 180 if thats of any help. My plugs were black (rich mixture?) and are getting cleaned right now.

                        after plugs are clean ill run it again with stock jet size. And decide if its a jet size issue or a plug issue. Thanks again phil.

                        Comment


                        • #13
                          Originally posted by Snareguy View Post
                          ​​​​​​


                          if im on pods + 4-1 exhaust + no baffle (open header style?) id have to add 13 sizes bringing me to
                          47.5/150 ?
                          No, you don't want to do this. The max you should need is 45 pilot and 142.5 mains.
                          2H7 (79)
                          3H3

                          "If it ain't broke, modify it"

                          Comment


                          • #14
                            FWIW, Niche Cycle has genuine Mikuni parts. Prices are good and response is quick.
                            Marty (in Mississippi)
                            XS1100SG
                            XS650SK
                            XS650SH
                            XS650G
                            XS6502F
                            XS650E

                            Comment


                            • #15
                              Thanks for that link jetmech!!! I just may get me some things there today!! You should be getting your referral fees in the mail from them shortly
                              1981 Midnight Special
                              Formerly had a Seca 550 and boy was it fast!!

                              Comment

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