850 high idle every so often

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  • gs850cafe
    • Feb 2026

    #1

    850 high idle every so often

    its been doing it a week now...not everytime i stop , but sometimes it will idle at close to 3k...if i keep riding it it goes away...or sometimes a high rev will fix it to

    all the maintence is done...just curious as to why its doing it all of a sudden..
  • Guest

    #2
    One of the choke plungers sticking? air leak somewhere, maybe one of the intake o-rings busted a hole? throttle cable sticking? or cable is grabbing somewhere?

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    • kdo58

      #3
      I am rebuilding my top end and had replaced the intake orings a couple of years ago some of the allen bolts were loose sorta of surprised me.

      Comment

      • 850 Combat
        Forum Guru
        Past Site Supporter
        • Sep 2006
        • 6018
        • Spokane, WA, and Hampden, ME

        #4
        Air leak is what I would guess. A sticky mechanical advance in the ignition is common on English bikes, but I've never really heard of it on these. Puus, I wouldn't expect it to be that high.
        sigpic Too old, too many bikes, too many cars, too many things

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        • Guest

          #5
          You have an air leak somewhere as already stated. You've been on the site long enough you know the routine.Check your intake boots and o-rings

          Comment

          • gs850cafe

            #6
            Originally posted by hjfisk
            You have an air leak somewhere as already stated. You've been on the site long enough you know the routine.Check your intake boots and o-rings

            i figured an air leak...but wouldnt it do it all the time?

            Comment

            • Guest

              #7
              Originally posted by gs850cafe
              i figured an air leak...but wouldnt it do it all the time?
              Not necessarily with expansion and contraction as the bike heats up and cools things have a tendency to move, .

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              • Nessism
                Forum LongTimer
                GSResource Superstar
                Past Site Supporter
                Super Site Supporter
                • Mar 2006
                • 35791
                • Torrance, CA

                #8
                Crappy sync job can cause that. Lean carbs too.
                Ed

                To measure is to know.

                Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182

                Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846

                Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf

                KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection

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                • Gorminrider
                  Forum Sage
                  Past Site Supporter
                  • Aug 2012
                  • 4803
                  • British Columbia, Canada

                  #9
                  Intermittent problems, you really have to jump on them when they are happening...next time it does it, get thee to the side of the road (a safe spot) and maybe eliminate some of the obvious (as AZR said above :sticky throttle -maybe cable is routing wrong or frayed etc. ...)get yer fingers in the carb linkage and fiddle gently. Take a can of wd 40 or just oil next ride and squirt it round the intake manifold for airleaks. Tap the carbs (to free floats) you can get at ...
                  for me, the Vicinity of the last thing I "fixed" before a symptom developed, is the Vicinity I look hard at. I say vicinity, because it's not usually the "thing" itself- it's something I did "on the way" to the thing I fixed...

                  added: throttle cable routing.. Turn the handlebars side to side... it might be that it's hanging up a bit just when you make right turns but not left.maybe the cable clamp to the frame under the tank has come undone...
                  Last edited by Gorminrider; 03-02-2013, 07:32 PM.

                  Comment

                  • stockGS

                    #10
                    Would the outside temp cause somthing like this? I have been running my 850G on the freeway at about 70mph with the air temp at 50 F. Or does the outside temp not have any effect on a sealed air system?


                    Just curious.

                    Comment

                    • rustybronco
                      Forum LongTimer
                      Bard Award Winner
                      GSResource Superstar
                      Past Site Supporter
                      • Jul 2005
                      • 14961
                      • Marysville, Michigan

                      #11
                      Same thing happened to me on my 82 '850. One of the intake o-rings I had replaced after I first got the bike had split open (cracked).
                      De-stinking Penelope http://thegsresources.com/_forum/sho...d.php?t=179245

                      http://www.thegsresources.com/_forum...35#post1625535

                      Comment

                      • BassCliff

                        #12
                        Hi,

                        Picture from http://cycleorings.com/intake.html . <<-- Click to read more.



                        This is a flat, broken intake boot O-ring. You'll find intake repair procedures and suggestions on my little website.


                        Thank you for your indulgence,

                        BassCliff
                        Last edited by Guest; 03-04-2013, 05:30 PM.

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