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Rejetting 77 gs550 for pods and pipes

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    Rejetting 77 gs550 for pods and pipes

    So I'm a total noob.

    I am in the process of of rejetting my 77 gs550 for pods and pipes since the old air box was trashed. I see there is rarely see any mention of the pilot jet no. 2. which is 50. I am jetting for k&n pods and 4 in 1 exhaust with a mini muffler no baffle. I changed the mains to 92.5 and was still lean so I'm changing to 100 tonight and pilot no 1. to 17.5 and moved the needle 2 notches. Should i keep the pilot jet no. 2. how it is stock (i'm confused why its never mentioned). Also for these changes where would you suggest for a good starting point with the fuel mixture screws on the bottom?

    also I have

    I have replaced the manifold boots and o rings but it still seems like i have a vacuum leak it revs around 3k-4k once it reaches 3k on the throttle and won't come down unless i'm in gear and fiddle with the clutch lever. idle stays around 1200. I haven't checked the points or valves yet as I don't have a clue what I'm doing. Could the valves or points cause this issue?

    thanks

    any help would be much appreciated and if any of you are in portland area and wouldn't mind showing me some things i would greatly appreciate an help i can get. I've learned a ton reading this forum but still nervous to attempt some things.
    Last edited by Guest; 08-26-2014, 06:49 PM.

    #2
    I can't really offer any technical help (I paid to have mine rejetted on a dyno), but I think most would agree 1200 is a nice healthy idle.
    1982 GS1100E V&H "SS" exhaust, APE pods, 1150 oil cooler, 140 speedo, 99.3 rear wheel HP, black engine, '83 red

    2016 XL883L sigpic Two-tone blue and white. Almost 42 hp! Status: destroyed, now owned by the insurance company. The hole in my memory starts an hour before the accident and ends 24 hours after.

    Comment


      #3
      When you play with mixtures it's best to do one thing at a time. Change the mains..... run it, raise the needles... run it and so on. Getting it right is time consuming.
      Good luck

      Comment


        #4
        I think on my wife's, we ended up with 102.5 mains, but I think a 100 might be slightly better for her particular bike with pods and pipes. Dual exhaust with straight through glasspacks.

        the stock pilot jets work great, the bike idles GREAT, no lean hanging at all. Try raising your needles one notch from stock.that would mean putting the clip in one slot lower, which actually raises the needle higher, as the clip sits stationary in the carb slide.
        Last edited by Chuck78; 08-25-2014, 11:31 PM.
        '77 GS750 920cc heavily modded
        '97 Kawasaki KDX220R rugged terrain ripper!
        '99 Kawasaki KDX220R​ rebuild in progress
        '79 GS425stock
        PROJECTS:
        '77 Suzuki PE250 woods racer
        '77 GS550 740cc major mods
        '77 GS400 489cc racer build
        '76 Rickman CR1000 GS1000/1100
        '78 GS1000C/1100

        Comment


          #5
          Maybe read the Pipes, Pods, Panic sticky?
          1978 GS 1000 (since new)
          1979 GS 1000 (The Fridge, superbike replica project)
          1978 GS 1000 (parts)
          1981 GS 850 (anyone want a project?)
          1981 GPZ 550 (backroad screamer)
          1970 450 Mk IIID (THUMP!)
          2007 DRz 400S
          1999 ATK 490ES
          1994 DR 350SES

          Comment


            #6
            When tuning a bike, the very first step is making sure the valve clearances are correct. Only then should you start with carb tuning, etc...

            Comment


              #7
              Thanks for the responses so far. I've read the sticky about pods and many other pod related threads. I guess I'll just have to dive into checking the valves and points I just wish I had somebody to run through it with me. I bought the tools I need, maybe I'll take a go at it this week. Any one have any thoughts on the pilot jet no. 2? Or symptoms that could be causing the rev sticking?

              Thanks

              Comment


                #8
                I don't recall a pilot jet number two on those carbs, are you referring to the pilot air jet? That is typically fixed and is a brass orifice that is pressed into the carb body. there is also a main air jet (Fixed/preseed in also) and needle jet, & the needle jet does not typically need changing unless you do a big bore kit.
                '77 GS750 920cc heavily modded
                '97 Kawasaki KDX220R rugged terrain ripper!
                '99 Kawasaki KDX220R​ rebuild in progress
                '79 GS425stock
                PROJECTS:
                '77 Suzuki PE250 woods racer
                '77 GS550 740cc major mods
                '77 GS400 489cc racer build
                '76 Rickman CR1000 GS1000/1100
                '78 GS1000C/1100

                Comment


                  #9
                  Rev sticking either means too lean (likely vacuum leak -boots/boot o-rings/carb o-rings) or could be that you are fouling plugs at idle but before they foul & idle at 1000-ish, they are fully firing & this "induces" the "high" idle.

                  Also could be sticking mechanical advancer arms/weak advancer springs, but tthat' even more of a long shot.
                  '77 GS750 920cc heavily modded
                  '97 Kawasaki KDX220R rugged terrain ripper!
                  '99 Kawasaki KDX220R​ rebuild in progress
                  '79 GS425stock
                  PROJECTS:
                  '77 Suzuki PE250 woods racer
                  '77 GS550 740cc major mods
                  '77 GS400 489cc racer build
                  '76 Rickman CR1000 GS1000/1100
                  '78 GS1000C/1100

                  Comment


                    #10
                    Originally posted by parkerross View Post
                    Thanks for the responses so far. I've read the sticky about pods and many other pod related threads. I guess I'll just have to dive into checking the valves and points I just wish I had somebody to run through it with me. I bought the tools I need, maybe I'll take a go at it this week. Any one have any thoughts on the pilot jet no. 2? Or symptoms that could be causing the rev sticking?

                    Thanks
                    Where are you located? I am tuning a 78 550E at the moment and I could offer some advice or help if close. The jet you are referring to, just leave as is. the 50 works just fine.

                    The rpm hang up might be caused by a vacuum leak. Try small short sprays of carb cleaner around the intake boots. The valve adjustment should be first though.

                    Comment


                      #11
                      I looked up the parts fiche diagram for a refresher, the vm22ss's don't use the same type of pilot jets that the larger vm's use,& the pilot jet is basically a 2 piece jet, with the emulsion tube being jet #2 (I believe that is the coreect terminology). They are stacked in the same pilot hole. Stock should be just fine unless you run open velocity stacks or are using non-gs550 vm22's.
                      '77 GS750 920cc heavily modded
                      '97 Kawasaki KDX220R rugged terrain ripper!
                      '99 Kawasaki KDX220R​ rebuild in progress
                      '79 GS425stock
                      PROJECTS:
                      '77 Suzuki PE250 woods racer
                      '77 GS550 740cc major mods
                      '77 GS400 489cc racer build
                      '76 Rickman CR1000 GS1000/1100
                      '78 GS1000C/1100

                      Comment


                        #12
                        Originally posted by 78550GS View Post
                        Where are you located? I am tuning a 78 550E at the moment and I could offer some advice or help if close. The jet you are referring to, just leave as is. the 50 works just fine.

                        The rpm hang up might be caused by a vacuum leak. Try small short sprays of carb cleaner around the intake boots. The valve adjustment should be first though.
                        I'm located in Portland, OR it looks as you are in Ohio, I doubt I'm close enough ha. Thanks for the offer though. The intake boots should be good as I just replaced them when I got the bike a couple months ago. Even if the o rings in the carbs don't have any visible damaged is it a good idea to replace them? When I cleaned the carbs I didn't notice any, I just assumed they we're in good condition still.

                        Comment


                          #13
                          Go ahead and order a set of O-rings for the carb internals. I would much rather KNOW they are new than assume.

                          Comment


                            #14
                            cool, I just ordered them.

                            Comment


                              #15
                              Can I follow this video for doing valve check even though its not exactly the same as gs550? I can't find any detailed video with an older gs, but from the little I know about valves they look very similar to the written tutorials i've read. But I just need a visual while following along with the manual for the correct specs. https://www.youtube.com/watch?v=jIL0eMzRPF8

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