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    FYI jetting info

    Got this from another site

    Jetting Recommendations

    This article recommends "rule of thumb" jetting changes based on specific modifications from stock configuration.

    Main jets:

    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)
    Add up all the jet size increases and subtract one. (Remember they go in steps of 2.5 for each jet size)

    Pilot jets:
    1 pilot jet size for every 3 main jet size increase

    #2
    XS11 site. The jetting chnages are about right

    Comment


      #3
      1 jet size for drilling out the bottom of the airbox

      I WONDER IF THEY MEAN THE AIR FILTER BOX??

      Comment


        #4
        Re: FYI jetting info

        Ok here one for you experts, anyone know of a 4 to 1 Vance and Hines headers for a 1980/81 GS1100 that does not require a carb rejet?

        Comment


          #5
          Re: FYI jetting info

          Never mind I just answered that question myself, here is the answer.

          model numbers 12009P/ 12002PCO/12001 "GS1100 '80-'83 -> Remove the stock airbox lid and increase the main jet to a 122.5. The pilot jet
          should be raised to a 47.5." (ref: http://www.vanceandhines.com/download/S110IN.pdf)

          So now I, and all of you folks know.


          Originally posted by Evil Hobbit
          Ok here one for you experts, anyone know of a 4 to 1 Vance and Hines headers for a 1980/81 GS1100 that does not require a carb rejet?

          Comment


            #6
            Re: FYI jetting info

            Originally posted by Evil Hobbit
            Ok here one for you experts, anyone know of a 4 to 1 Vance and Hines headers for a 1980/81 GS1100 that does not require a carb rejet?
            I have a V/H 4-1 pipe on my GS1000 and it flows freer than a stock exhaust, so yes, the jetting needs to be changed. Your 1100 would be no different. Any quality 4-1 pipe would require at least larger main jets and often jet-needle changes too. If you run that pipe with stock jets, you will run leaner.
            And on the seventh day,after resting from all that he had done,God went for a ride on his GS!
            Upon seeing that it was good, he went out again on his ZX14! But just a little bit faster!

            Comment


              #7
              Re: FYI jetting info

              Originally posted by KEITH KRAUSE
              Originally posted by Evil Hobbit
              Ok here one for you experts, anyone know of a 4 to 1 Vance and Hines headers for a 1980/81 GS1100 that does not require a carb rejet?
              I have a V/H 4-1 pipe on my GS1000 and it flows freer than a stock exhaust, so yes, the jetting needs to be changed. Your 1100 would be no different. Any quality 4-1 pipe would require at least larger main jets and often jet-needle changes too. If you run that pipe with stock jets, you will run leaner.
              not trying to be mean just not sure how the engine will be able to run leaner just from an exhaust change. I have both the factory exhaust and a D&D race exhaust (4into1) and do not require a jet change for either.the only time I needed to change my jets was putting pod filters on. stage 1 for factory exhaust and stage 3 for race exhaust with the pod filters. none needed for factory air box. I have done the swaps many different times an found no need to rejet with the factory air box on for either exhaust. (I don't have the lean problem but that may be attributed to my meticulis syncronisingof my carburators)

              please dont give a long drawn out reply just a brief one so I may understand your logic.

              thanx

              Comment


                #8
                A brief reply? V&H, Kerker and many other quality manufacturers and jet kit makers recommend jet changes. They know more than me. I do what they and the sparkplugs say. My jetting experiences are different than yours.
                And on the seventh day,after resting from all that he had done,God went for a ride on his GS!
                Upon seeing that it was good, he went out again on his ZX14! But just a little bit faster!

                Comment


                  #9
                  true true just seems wierd to me :?

                  Comment


                    #10
                    Originally posted by KEITH KRAUSE
                    A brief reply? V&H, Kerker and many other quality manufacturers and jet kit makers recommend jet changes. They know more than me. I do what they and the sparkplugs say. My jetting experiences are different than yours.
                    I was just quoting the instaltion guide (ref: http://www.vanceandhines.com/download/S110IN.pdf) at this link for a particular exhaust for a GS1100. If you check the link you will see that other models will require a carb rejet, the 1100 requires a different adjustment. Also, I am sure that other manufacturers exhausts will have specific requirements by motor size for their exhausts.
                    Good riding, for those that live in places where you can. It got all the way to 41 degrees here in Cincinnati yesterday.
                    Chuck a.k.a. Evil Hobbit

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