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What did I do!? SUPER high rev's when I turn the bike on.

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    What did I do!? SUPER high rev's when I turn the bike on.

    1981 GS850

    As soon as I hit the starter button the bike revs VERY VERY high. Throttle increases the rev's a little bit, as does turning the idle speed knob.

    What I worked on today:
    -Replaced throttle cable
    -Installed choke cable
    -Some electrical work
    -Adjusted the clutch a smidge.

    What I've tried:
    -Ensured that the throttle cable is snapping back all the way, as in ensured that the throttle cable isn't pulling up on the throttle plate while resting.
    -Ensured that the choke cable is going it's full travel when pulled, so similarly made sure that the choke isn't on while the knob is all the way down.
    -Adjusted the idle screw underneath the carbs to make it magically didn't screw all the way in or all the way out. It did increase the speed a bit when I turned the screw in.

    I've been on my feet too long today so I'm going to sleep on it. Tomorrow I can take off the throttle cable and choke just to make sure it isn't the problem. I did ride the bike yesterday and it was running pretty well aside from a sketchy throttle and no choke cable.
    Open to any ideas... thanks!!!!!

    #2
    On the face of it, nothing you have done would cause the high rpms in and of itself.

    Just because the throttle snaps back doesn't mean that it is closing all the way. Can you see that it is REALLY closing down on the throttle stop at the carb?

    Did you reroute the throttle cable a different way?

    Is it a shorter cable than the one you replaced?
    '83 GS650G
    '83 GS550es (didn't like the colours in the 80's, but they've grown on me)

    Comment


      #3
      Originally posted by BigD_83 View Post
      On the face of it, nothing you have done would cause the high rpms in and of itself.

      Just because the throttle snaps back doesn't mean that it is closing all the way. Can you see that it is REALLY closing down on the throttle stop at the carb?

      Did you reroute the throttle cable a different way?

      Is it a shorter cable than the one you replaced?
      I didn't measure both cables but it might be a good idea. I disconnected the throttle and it didn't snap back any more, pushing down on the top end just bends out the bottom. Cables were routed the same.

      Comment


        #4
        Either the carbs aren't closing all the way (likely), or the intake boots are leaking (also likely if you haven't changed the O-rings and you levered on the carbs to remove them and change the cable).
        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

        Comment


          #5
          Or your choke is stuck open.
          http://img633.imageshack.us/img633/811/douMvs.jpg
          1980 GS1000GT (Daily rider with a 1983 1100G engine)
          1998 Honda ST1100 (Daily long distance rider)
          1982 GS850GLZ (Daily rider when the weather is crap)

          Darn, with so many daily riders it's hard to decide which one to jump on next.;)

          JTGS850GL aka Julius

          GS Resource Greetings

          Comment


            #6
            Is this something new? Or has it always been happening? Your carbs could be way out of sync too

            Comment


              #7
              I did that just after fitting an aftermarket clutch cable. It was holding the throttle open. Those wire guides are there for a reason.
              97 R1100R
              Previous
              80 GS850G, 79 Z400B, 85 R100RT, 80 Z650D, 76 CB200

              Comment


                #8
                Originally posted by Brendan W View Post
                I did that just after fitting an aftermarket clutch cable. It was holding the throttle open. Those wire guides are there for a reason.
                Alright so tonight, I'll remove the choke cable completely and test. Following that I'll reroute all cables to ensure proper routing. Following that I'll explore air leaks. Hopefully we'll find something.

                Comment


                  #9
                  Originally posted by Brendan W View Post
                  I did that just after fitting an aftermarket clutch cable. It was holding the throttle open. Those wire guides are there for a reason.
                  It's also relatively easy to bend the bracket that holds the throttle cable. Been there, done that...
                  '83 GS650G
                  '83 GS550es (didn't like the colours in the 80's, but they've grown on me)

                  Comment


                    #10
                    Originally posted by Sphynx88 View Post
                    Alright so tonight, I'll remove the choke cable completely and test. Following that I'll reroute all cables to ensure proper routing. Following that I'll explore air leaks. Hopefully we'll find something.
                    Hopefully you wouldn't need to remove the clutch cable or even lift the tank. It should be possible to see if it's touching the throttle mechanism. If it's strayed off line back between 1 & 2 carbs just pull it forward out of the way.
                    97 R1100R
                    Previous
                    80 GS850G, 79 Z400B, 85 R100RT, 80 Z650D, 76 CB200

                    Comment


                      #11
                      Didn't get a chance to look at it last night, however I did turn it on breifly and move the throttle cable with my hand. It changed the speed a bit so I'm guessing I goof'd on the routing.

                      Comment


                        #12
                        Hmmmmmmmmmmmmmmmm............

                        I took the tank off and manually fed it gas. When I completely disconnected the throttle it acted normal. I ensured it was routed properly then reinstalled and worked perfectly. Hooray. Put the tank back on..... DID IT AGAIN. Grrrrr.

                        What in the heck. I'll need to pull the tank and triple check one of the clips didn't come undone and shift the routing but the cable isn't catching on anything. This is just the strangest thing.

                        Comment


                          #13
                          PROBLEM SOLVED: thanks for everyone's help. Took it apart and realized there was a little interference between the choke and throttle as someone mentioned. CASE CLOSED. woohoo!

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