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    jet size

    hey guys, own a 1982 gs1100ez and it has a vance and hines race 4 into 1 pipe, and i just bought k&n individual pods for it. i also just purchased a factory pro
    3.0 kit for the carbs to be rejected. the kit came with 130 and 132.5 main jets
    i put in the 132.5 jets and the bike is still getting flat between 7-9k. i set the float heights to 22.4mm. the low and midrange is in my eyes perfect. smooth and powerful. i had already also synchronized the carbs. i pulled a spark plug and it looks lean for sure. i called factory pro and they said i may need a bigger main jet size. so he is going to send me the next two sizes up for free. at least they seem to be taking care of me on that but from what i have read on here it seems everyone has been good with running around 125s in their bike. any ideas?

    #2
    Originally posted by Gs1100e82 View Post
    hey guys, own a 1982 gs1100ez and it has a vance and hines race 4 into 1 pipe, and i just bought k&n individual pods for it. i also just purchased a factory pro
    3.0 kit for the carbs to be rejected. the kit came with 130 and 132.5 main jets
    i put in the 132.5 jets and the bike is still getting flat between 7-9k. i set the float heights to 22.4mm. the low and midrange is in my eyes perfect. smooth and powerful. i had already also synchronized the carbs. i pulled a spark plug and it looks lean for sure. i called factory pro and they said i may need a bigger main jet size. so he is going to send me the next two sizes up for free. at least they seem to be taking care of me on that but from what i have read on here it seems everyone has been good with running around 125s in their bike. any ideas?
    Some engines need a bigger jet change than others. Built on Thurday morning, perhaps. Some riders will say one jet size is good, but they really don't know how to test. Some jets are not made accurately, some jet companies use different numbering schemes. I don't know what Factory Pro uses.

    Use what your engine needs, nothing else matters. I'd try the biggest one he gives you first. But with CV carbs, this will effect the low and midrange that was once perfect. You'll have to perfect them again.
    http://img.photobucket.com/albums/v5...tatesMap-1.jpg

    Life is too short to ride an L.

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      #3
      thanks! has anyone used factory pro?

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        #4
        The 3133 dyno jet kit stage 3 is dj132 and dj138. That cooresponds to mikuni mk122.5 to mk127.5 (roughly). If you are going above MK 130 you must have some engine work done and you are not stock.

        My 1166 with 4:2:1 is running a mk135 main and that is the smallest main jet I have ever heard of on an 1166. Besides the pipe largely due to the head work I head done. If you are really stock I would say you are too big already.

        All my numbers are based on extensive tuning using an LM-2 WB O2 sensor and associated data logging.
        Last edited by posplayr; 05-04-2014, 06:28 PM.

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          #5
          The other small point that you missed is how to jet a bike with cv carbs from the FP website.


          You start with the main. Till it is set nothing else matters.

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            #6
            I have Factory Pro needles I bought from Rapid Ray on this site - I'm running a 140 mains with Vance and Hines Supersport pipe, but K&N knockoff pods. What clip position are you running?
            -1980 GS1100 LT
            -1975 Honda cb750K
            -1972 Honda cl175
            - Currently presiding over a 1970 T500

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              #7
              i had them set third from the top as said to start and that was the best running and i had raised them one before calling factory pro. i believe its too rich now mid level and I'm going to go back to 3rd from the top. when i get the new mains I'm guessing it will be 134 or 135?

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                #8
                posplayr i did know that the main jet is the starting point. it was a cold 45 and rainy day so i tuned it up with the 132.5 and then tried it the following day. the plug does not look at all rich though. they are even slightly "white". i took 118's out of it and it had the vance and hines pipe, and knock off pods that were much more restrictive. when i bought the k&n pods the bike really hated them with the 118s. thats why i went to rejet in the first place. I'm not sure what you meant by the jet sizes. does factory pro use minuki jets? opposed to dyne jet?

                Comment


                  #9
                  Originally posted by Gs1100e82 View Post
                  posplayr i did know that the main jet is the starting point. it was a cold 45 and rainy day so i tuned it up with the 132.5 and then tried it the following day. the plug does not look at all rich though. they are even slightly "white". i took 118's out of it and it had the vance and hines pipe, and knock off pods that were much more restrictive. when i bought the k&n pods the bike really hated them with the 118s. thats why i went to rejet in the first place. I'm not sure what you meant by the jet sizes. does factory pro use minuki jets? opposed to dyne jet?

                  Yes Factory pro only sells OEM jets as far as I recall. Their kits have OEM jets.
                  DJ sells only DJ jets which flow similar to the same size as a MK is you remove 10 points (e.g. DG130 is approx MK120 ).

                  If you know that you start on the Main then why make the comment that everything else is solid except the 7K-9K range? Once you get the main dialed the bottom end will probably need tweaking based on where ever you end up.

                  Also you have not specified if the engine is stock or not? With 4:1 and K&N type pods you should not need anything else other than the DJ132-DJ138 range that is in the DJ-3133 kit.



                  Also while it is not recommended by DJ, it is conventional wisdom that you increase your pilot size from 45 to 47.5 when jetting for a 4:1 exhaust (as opposed to 4:2:1)

                  Comment


                    #10
                    i stated that the low and midrange is set well because it is. I'm not saying i tuned it to run well. i just installed the factory pro 3.0 kit that was suggested to me by factory pro. so currently i have the 132.5 main jets and i believe a 50 pilot jet.
                    i don't currently have the kit specs with me. again though i pulled the plugs and they aren't even golden or dark, they look lean.

                    Comment


                      #11
                      also i don't think my bike has any internal upgrades. i bought it 3 years ago. are the dj jets smaller on the head? the ones i took out were 118's and they had a smaller head on them. if so that would make them equal to 128 mk right?

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                        #12
                        Originally posted by Gs1100e82 View Post
                        i stated that the low and midrange is set well because it is. I'm not saying i tuned it to run well. i just installed the factory pro 3.0 kit that was suggested to me by factory pro. so currently i have the 132.5 main jets and i believe a 50 pilot jet.
                        i don't currently have the kit specs with me. again though i pulled the plugs and they aren't even golden or dark, they look lean.
                        We'll good luck

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                          #13
                          sorry but I think I'm confused by this at this point posplr

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                            #14
                            Originally posted by Gs1100e82 View Post
                            sorry but I think I'm confused by this at this point posplr
                            If you reread my posts it might become more clear; I tend to be sparing with words till I figure out if someone is paying any attention.

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                              #15
                              posplyr, did you read my post asking about head size of the dj jets? right before you said good luck

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