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    Help Me Diagnose An Engine Noise?

    Help Me Diagnose An Engine Noise?

    -Back Story-
    A couple weeks ago I pick a up a 79 GS1000L. It was in pretty bad shape, which was exactly what I was looking for. I've been keeping my eye out for the right restoration/customization project, and I pulled the trigger on this one. I am taking this thing one step at a time making sure the engine and transmission seem solid before I get to deep into fixing the bike up.

    -Problem-
    Now that I have the bike running and somewhat idling ok I am noticing a noise coming from what sounds like the bottom left side of the engine. It is most noticeable at low rpm, really right as the bike feels like it might stall. It is seemingly fine with the rpm's up. It's a rattly, slightly knocky sound.

    My first thought is the starter clutch. The bike cranks over fine and doesn't seem to have any problems there, but from what I've read on the forums a loose starter clutch may be the culprit.

    Any thoughts on where I should begin to diagnose this sound/problem. Begin with the starter clutch, or is there something else I should be considering first? Anyone have a link to a thread showing how to remove the stator rotor and examine the starter clutch? Is this job possible without investing a bunch of money into specialty tools?

    Thanks in advance for your insights.

    #2
    A video would help alot here....

    Comment


      #3
      Was just thinking about shooting some video or capturing some audio at least. I will try to get something up tomorrow, thanks for the the suggestion.

      Comment


        #4
        I'm no Guru on these bikes, but if you shoot a video you can take a wooden broom handle and cut it off to about three feet. Find the noise's best point of origin by placing one end of the handle to your ear and the other end can be placed on the engine (place to place) until you hear it best. Then you can also rest the camera on the stick to record mainly that sound.

        (Dont try this while riding)

        Comment


          #5
          You can pull the side cover off in about 5 minutes and find out

          You've already spent more time than that posting and reading the responses
          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
            Thanks Big T, I have had it off now twice.

            The first to find out that I was missing the 2 washers that go with the starter idle gear. I replaced those thinking that maybe without the washers there was play in the gear that was causing the noise when the bike would run. It may have helped some but it didn't solve the problem.

            Am I missing something that would tell me if it's the starter clutch without pulling off the magnetic rotor? Just asking people's thoughts before I invest the time and money on tools to pull it apart if there is something else I should be looking into first. Thanks

            Comment


              #7
              Well, on further investigation this morning it seems like the noise is coming more from the transmission area.

              It does not go away when I pull in the clutch, it still happens in neutral, but seems to be worse the higher the gear you're in. This is all while shifting through while the bike is on the center stand.

              It shifts a little hard too. It doesn't like to go into 1st or 2nd about 80% of the time from a stop. However it seems to shift ok while rolling. In fact I've noticed with the bike off i can't get it to go from neutral to 1st but if I press down on the gear shift and reach back and turn the rear wheel about 1.5in it drops in just fine. But again from a stop it feels like it kind of grinds into gear.

              I believe I have the clutch cable adjusted properly.

              Any thoughts? I will be trying to post some video later today. Thanks

              Comment


                #8
                It sounds like a rattly clutch basket to me. This is a regular problem with these bikes, comes up from time to time. Do a search and you will find something. And don't go buying special tools for these bikes, they can be made yourself with a welder and a bit of ingenuity.

                BTW I had the clutch basket problem on my motor.

                Comment


                  #9
                  Your explanation of not being able to change gears or get the transmission out of gear unless the rear wheel is turned a little is normal. One of the shafts/gears needs to move a little so one gear's teeth can slip into mesh with it's mating gear.

                  Comment


                    #10
                    Thanks Don, I took apart the clutch to find that it was a bit loose and was able to tighten it down some. That seemed to help some of the noise.

                    There is still a remaining noise that I'm pretty sure is coming from the starter clutch. Took the stator cover off today and shot this video. Is it normal for the starter clutch to be loose like that? Also I tried to see about pulling the stator rotor but couldn't break the bolt loose. Any links or helpful tricks to be able to take this all apart to get a better idea of the starter clutch?

                    Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube.

                    Comment


                      #11
                      Hi There,
                      Just wondering if you've gotten to the bottom of this. I've got an 81 gs1100e that's got a weird knock, too. Trying to figure out where I should start.

                      Comment


                        #12
                        Hi Banausic, The problem was two fold, a lesser knock and a louder primary knock.

                        The lesser knocking noise was from the clutch basket, the main holding nut was just loose. I tightened it down and that seemed to take care of it.

                        The main noise was from the starter clutch being loose. The 3 bolts that hold the starter clutch to the stator rotor had worked themselves out a little, which was causing the starter clutch to knock around.

                        I removed the stator rotor, starter clutch and flywheel, examined everything, tightened the bolts for the starter clutch back down with red threadlock and reassembled. The noise went away!

                        Hope that helps, Good Luck!

                        Comment


                          #13
                          Thanks and it's good to hear you had some luck

                          Cheers

                          Comment

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