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  • Need to Re-jet?

    Hey,
    I put a tear drop intake that uses the KNN-E-3495 element and bike seams to be sluggish on take off. Do you need to re-jet the carb if this is all I changed? I have read about this before but can't seam to find it right off.
    Thank you
    Life is tough, it's even tougher if your stupid----John Wayne

  • #2
    What filter was on it before? Shouldn't have to rejet but if it was close to the leaner side before the change it may not hurt to go up a notch on the pilot.

    2000 Roadstar 1600 - BAK, Pumpless, Curt's manifold, Mikuni HSR42 Freedom Combat Pipes Jumbo Strong bags, PPG 'HellFire' Paint.

    Comment


    • #3
      Your profile shows you have aftermarket exhaust on the bike in which case a rejet is definitely needed.

      Comment


      • #4
        It had the stock air cleaner on it before and the exhaust looks like long shots but there are no markings on them.
        Life is tough, it's even tougher if your stupid----John Wayne

        Comment


        • #5
          Mike, pull your choke about halfway out, and see it that helps, if it improves on the lower end, you are probably running lean.

          mine is set a tad lean, but here's the specks:

          175 main jet, 37.5 pilot jet, Barrons needle on 3rd clip, PMS 3.75 turns out from light seat.

          Comment


          • #6
            Hey Randy, Long time no hear How you doing? Ya, I pulled the choke out and it seamed to help a bit, what jets or settings should I start at?
            Life is tough, it's even tougher if your stupid----John Wayne

            Comment


            • #7
              I'm doing pretty good.
              I got the Barron's kit, swapped out the jets and needle, ran like a rapped ape after that, still have a small decel. backfire, but it don't bug me. I just followed the instruction in the Tech Articles, easy as pie!! Your bike a 1600, or a 1700?

              Comment


              • #8
                Mine is the 1600, I was just reading thru the tech article on the carb and was wondering if it could be as easy as just adjusting the PMS. Going to go play with it.
                Life is tough, it's even tougher if your stupid----John Wayne

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                • #9
                  good place to start.

                  Comment


                  • #10
                    Originally posted by davej View Post
                    Your profile shows you have aftermarket exhaust on the bike in which case a rejet is definitely needed.
                    This was good advice. ^^^^^^^^

                    Tweaking the PMS, is a poor substitute for proper jetting.

                    Comment


                    • #11
                      Mike,
                      Changing the stock air box to a better breathing box will require you to re-jet the main jet on your bike. The after market pipes do not require you to change the jets. If your carb is stock, take a look at the jet number and go the next size up. Adjustment to the excelerator pump might be needed. Changing the pilot jet is not needed. Air flow from the different boxes shouldn't change the idle and off idle system.
                      I hope this helps.
                      Duke.

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                      • #12
                        Thanks Duke, that sounds like the way I need to go. Where is a good place to get the right jets? the dealer? and should I replace the needle with the barons needle?
                        Life is tough, it's even tougher if your stupid----John Wayne

                        Comment


                        • #13
                          You can still find Speedstar carb kits at Amazon, EBay, And a few dealers. These kits have jets, pilot jets, and a adjustable needle that will do the job. If you are changing the needle, than you will have to play around with the settings a little to get it dialed in for your bike. It's not to hard to do, just make one adjustment at a time so you know what works, and what doesn't work. When you get it dialed in, you'll be more one on one with that living air pump. Duke.

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                          • #14
                            Cool, got one coming.
                            Life is tough, it's even tougher if your stupid----John Wayne

                            Comment


                            • #15
                              Originally posted by Duke View Post
                              Mike,
                              Changing the stock air box to a better breathing box will require you to re-jet the main jet on your bike. The after market pipes do not require you to change the jets. If your carb is stock, take a look at the jet number and go the next size up. Adjustment to the excelerator pump might be needed. Changing the pilot jet is not needed. Air flow from the different boxes shouldn't change the idle and off idle system.
                              I hope this helps.
                              Duke.
                              Duke you are almost correct about the pilot jet. Changing the pilot is not required according to the jet kit instructions but will give the best jetting results. You are riding quite a bit in the pilot circuit at low speeds. When you change the intake and exhaust you are leaning the fuel mix in "ALL" circuits not just the main circuit.In the past your advice was given and there were constant carb issue threads. I personally done testing with after market air filter and different exhaust. My test uncluded Dyno's at the dealership for some and I continued testing after my purchase of a live AFR meter on my bike to get actual live Data in a real life riding situation. That testing resulted in a change of the pilot jet and has resolved 100's of member carb issue with no ill effect on MPG or anything else. It took care of off idle hesitations and low speed surging, also pms screws vibrating then falling out due to having to be too many turns out to run half way decent.

                              Also speedstar kits are almost like finding a unicorn and the Speedstar kit does change the pilot jet.

                              Comment


                              • Duke
                                Duke commented
                                Editing a comment
                                Davej you said: In the past your advice was given and there were constant carb issue threads.
                                Could you, or would you please direct me to any of those post? I'm trying to figure out if there out there any where.

                              • davej
                                davej commented
                                Editing a comment
                                Duke I didn't say that there were constant carb issues based on my jetting advice. I said before my testing the jetting advice given with the stock pilot jet that there were constant carb issues. You would have to go back about 8-9 years to find them. Also when using the instructions given by any of the kit kits they start out at setting the pms at 3-3 1/2 turns. The larger pilot jets(37.5 for the 1600's and 40 for 1700's) Has been tested and been working remarkably for 100's of members for years now.

                              • Duke
                                Duke commented
                                Editing a comment
                                Ok, I understand. I STAND CORRECTED, my bikes are running the # 35 pilots. My altitude is 5200'. I've built 4 carbs for local bikes in my area, and they are very happy with starting, performance, and fuel mileage. Thank you.

                            • #16
                              Mike
                              the best thing you can do is to order a Barons kit and also order a 37.5 pilot jet separately (it don't come in the kit). That is the most common kit used and you will get the best advice buying that kit. If you get a Barons kit you will not have to play games as Duke has suggested above. That is the old way of doing things. Get a Barons kit and your jetting will be
                              167.5 main jet
                              37.5 pilot jet
                              Needle clip in the 4th groove with 1 silver washer and plastic spacer under the clip
                              PMS set at 2 1/2 turns out
                              This jetting is proven thru literally 100's of members here with 1600's and no messing around making any changes. Use these settings and jets and install the carb and ride with nothing else to mess with.
                              Don't mess with the float and the acc pump should already be set properly from the factory (Unless someone has messed with it in the past). It should start to squirt as soon as you start to twist the throttle and squirt thru about 1/2 - 2/3rd of your throttle twist. Basically if you haven't had an issue with a hesitation on acceleration in the past it is more than likely just fine.

                              Comment


                              • Duke
                                Duke commented
                                Editing a comment
                                We are always dialing in our bikes,that's the fun. Guess we are all doing it the old way if we are using carbs. As Dave said, he did several test and I know we all have. Start with what you think will work with your bike, and go from there. It's all of our input that opens our minds to different ideas and help. We are all just trying to help one another, not play games. I love this form.

                              • davej
                                davej commented
                                Editing a comment
                                Duke I wasn't suggesting that you were playing games,I was saying that by using the stock pilot jet you will have to play games with adjustments and will never get it to run as good as you will by using the new suggested jetting on this forum. It is truly a once and done jetting and no guessing or using what you "think" will work. All the guess work has been removed. We have advanced to using Live read real time AFR gauges and have refined the jetting process since the old days.

                            • #17
                              The thing to remember with Speedstar needles, is they are different from the Barons and DJ needles. The Speedstars are fat like the stock needle. The DJ and Barons needles are slimmer and have faster tapers.
                              The difference will be in what Main and clip position works best with the fatter needle.
                              Davej can chime in if I miss this, but I think he was running a 40 pilot, and 180 main on his 05, and clip in the 5th(he may have dropped this to the 4th).
                              The usual recommendation for a Barons or DJ needle on the 05, is a 40 pilot and a 172.5 Main, clip in the 4th, or even 3.5(clip in the 4th with only the fat spacer under the clip).
                              The Baron or DJ recommendations for a 1600, with aftermarket pipes and a more open intake, is a 37.5 Mikuni Pilot, and a 167.5 Mikuni Main(a170 Mikuni Main If the rev limit has been raised).
                              Davej was able to fine tune his jetting, because he tweaked it with an A/F guage he installed on his bike. Based on his experience on his 05, you may be similar on the clip position, but possibly be as fat as a 175 on the Main. I think a 172.5 at the very least to start with.
                              The nice thing is, the Speedstar kits as with the Barons, use Mikuni jets. DJ kits don’t.

                              Morning Dave. Lol I was pecking away while you were posting.

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                              • #18

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                                • #19

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                                  • #20
                                    Originally posted by SKWEARpeg View Post
                                    The thing to remember with Speedstar needles, is they are different from the Barons and DJ needles. The Speedstars are fat like the stock needle. The DJ and Barons needles are slimmer and have faster tapers.
                                    The difference will be in what Main and clip position works best with the fatter needle.
                                    Davej can chime in if I miss this, but I think he was running a 40 pilot, and 180 main on his 05, and clip in the 5th(he may have dropped this to the 4th).
                                    The usual recommendation for a Barons or DJ needle on the 05, is a 40 pilot and a 172.5 Main, clip in the 4th, or even 3.5(clip in the 4th with only the fat spacer under the clip).
                                    The Baron or DJ recommendations for a 1600, with aftermarket pipes and a more open intake, is a 37.5 Mikuni Pilot, and a 167.5 Mikuni Main(a170 Mikuni Main If the rev limit has been raised).
                                    Davej was able to fine tune his jetting, because he tweaked it with an A/F guage he installed on his bike. Based on his experience on his 05, you may be similar on the clip position, but possibly be as fat as a 175 on the Main. I think a 172.5 at the very least to start with.
                                    The nice thing is, the Speedstar kits as with the Barons, use Mikuni jets. DJ kits don’t.

                                    Morning Dave. Lol I was pecking away while you were posting.
                                    Good morning Gordon, Mike posted he has a 1600 that is why I gave him the 1600 jetting numbers. Mine is a 07 but you are correct with the numbers I was running with the speedstar kit. In fact i could have probably dropped the main 1 more time to a 177.5 and been fine. Do see a seller on Ebay that has some NOS speedstar kits but I would stay away from them.Installing one of the kits will just muddy things up in the future if someone else gets into the carb. The speedstar kit will also overjet the pilot circuit. Here are the instructions for the speedstar kit. Look at #5 for changing the pilot jet. That is why I'm confused as to why Duke recommends a Speedstar kit but say changing the pilot is not needed when that is Speedstars primary change in jetting with their kits. A 50 is way over doing it but a change is recommended. Here is what it says.

                                    "3.
                                    Remove the jet needle and replace it with the Jet Needle

                                    from the kit. Use the original
                                    plastic ring spacer, washers, C-clip (in the 5t
                                    h groove down from the top), spring, O-ring, and
                                    diaphragm spring seat.
                                    O-RING
                                    2
                                    3
                                    1
                                    DIAPHRAGM
                                    SPRING SEAT
                                    C-CLIP IN 5th
                                    GROOVE
                                    4
                                    2
                                    SPRING
                                    CAUTION:
                                    Do not put the clip in the 6th position on the
                                    Jet Needle to avoid damaging the jet needle holder in
                                    the slide.
                                    NOTE
                                    :
                                    The Jet Needle Washers

                                    , plastic Ring Spacer

                                    and the Jet Needle C-Clip

                                    are extra. Keep
                                    them in case you lose or damage the original pieces.
                                    4.
                                    Double-check that the Jet Needle is assembled
                                    correctly and reinstall it
                                    in the Piston Valve.
                                    5.
                                    Replace the original Pilot Jet in
                                    the Carburetor with the Pilot Jet-50

                                    .
                                    6.
                                    Remove the Float Bowl, being careful not to damage the Float Bowl Gasket. Replace the
                                    original Main Jet to work with
                                    the Long Drag Exhaust Pipes as follows:
                                    Primary
                                    Operation Elev
                                    ation
                                    Main Jet (starting point)
                                    Below 2000 ft. (below 607m)
                                    Main Jet -165

                                    2000 ft. (607m) or above
                                    Main Jet -160

                                    7.
                                    Locate the pilot air screw plug in the bottom
                                    of the carburetor. Using a 5/32-inch (4mm) drill
                                    bit with a drill stop at 5/32 inch, carefully dr
                                    ill through the plug. Screw a sheet-metal screw
                                    into the hole in the plug, and then pull on the screw with pliers to remove the plug.
                                    CAUTION:
                                    Be careful not to drill to deeply
                                    . Otherw
                                    ise the pilot air screw
                                    or carburetor can be
                                    damaged.
                                    8.
                                    Carefully turn the pilot air screw in (clockwis
                                    e) until it is lightly seated, then turn it out
                                    (counterclockwise) 3 to 3-1/2 turns.
                                    9.
                                    Reinstall the carburetor.
                                    After reinstalling the carburetor, check for proper throttle operation."

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