Announcement

Collapse
No announcement yet.

tach bouncing

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • tach bouncing

    tach not staying steady, bounces rpms. how do I stop this?

  • #2
    If the tach is jumping while running on a smooth surface it's probably electrical, so start by checking all the connectors to make sure they're clean and secure. Start with the one coming out of the right lower cover. It connects to the harness behind the fuse box, then runs up to the headlight bucket where the tach itself connects to the harness. If the tach is jumping only on bumpy surfaces, it could be loose in the bucket. Check your securing nuts first,if it still persists then the dampening bushings inside the bucket may need to be replaced. I've used rubber grommets on mine and it helped a lot.
    mack
    79 XS 1100 SF Special
    HERMES
    original owner
    http://i946.photobucket.com/albums/a...ps6932d5df.jpg

    81 XS 1100 LH MNS
    SPICA
    http://i946.photobucket.com/albums/ad305/mack-055/2.jpg

    78 XS 11E
    IOTA
    https://youtu.be/wB5Jfbp6SUc
    https://youtu.be/RaI3WYHSuWA



    Have recovery trailer and shop if you breakdown in my area.
    Frankford, Ont, Canada
    613-398-6186

    Comment


    • #3
      I had luck with spraying electrical connector spray inside the tach in the holes on the back after taking it out of the bucket. My tach wobble is 99% better. I got the spray at Wal-Mart
      1979 XS1100F
      1980 XS1100SG(First bike, sold)

      Other bikes
      1976 Kawasaki KZ400 (project)
      1983 Yamaha XV920 Midnight Special
      1984 Yamaha XT250 Enduro (project)

      Comment


      • #4
        I advise caution on the spray. Yes it's 'electrical' type spray, so I'd say just make sure you don't put too much in there and short something out, then you'd have no tach.
        Hi, my name is George & I'm a twisty addict!

        80G (Green paint(PO idea))
        The Green Monster
        K&N A/F, TC's fuse block, '81 oil cooler, TC's homemade 4-2 w/Mac Mufflers, Raptor 660 ACCT
        Got him in '04.
        bald tire & borrowing parts

        80SG (Black w/red emblems & calipers)
        Scarlet
        K&N A/F, TC's fuse block, WJ5, Shoei bags, Raptor 660 ACCT.
        Got her in '11
        Ready for the twisties!

        81H (previously CPMaynard's)
        Hugo
        Full Venturer, Indigo Blue with B/W painted tank.
        Cold weather ride

        Comment


        • #5
          If you know where to get a known good tach plug it in and see if the problem persists. If not your IC in your tach is probably bad and you need another tach. I've gone through a couple in the last 3 years.

          If it still does it with a known good tach then you probably have a connection problem.

          I tore into one in an attempt to repair it and thought I had it fixed but now the needle flattens out around 4K and isn't accurate at all after that.
          Greg

          Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.”

          ― Albert Einstein

          80 SG Ol' Okie;79 engine & carbs w/pods, 45 pilots, 140 mains, Custom Mac 4 into 2 exhaust, ACCT,XS850 final drive,110/90/19 front tire,TKat fork brace, XS750 140 MPH speedometer, Vetter IV fairing, aftermarket hard bags and trunk, LG high back seat, XJ rear shocks.

          The list changes.

          Comment


          • #6
            I took it off the bike, took it apart, sprayed, and let it sit for a few days to be sure it was dry before re-installing.
            1979 XS1100F
            1980 XS1100SG(First bike, sold)

            Other bikes
            1976 Kawasaki KZ400 (project)
            1983 Yamaha XV920 Midnight Special
            1984 Yamaha XT250 Enduro (project)

            Comment


            • #7
              several grounds come together at the voltage reg/rec mount, make sure they are clean and making good contact with reg/rec body and frame the reg/rec body is aluminum and can be oxidized
              where are we going, and why are we in this hand basket?
              Iowa the Beautiful Land 1980 XS1100SG

              Comment


              • #8
                While we're on the tach subject, what are you supposed to be taching at 60mph? I'm getting a little more than 4k in fifth. Bit more than 5k at 70mph in fifth.
                1990 Ninja ZX-10. It's the Silver Surfer. HI-YA!!

                2006 Yamaha XT-225. Yep, I take it on the interstate. It's Blue Butt.

                1982 Toyota 4x4. 22R Cammed, 38/38, 2" pipe, 20R head with OS valves, performance grind and other fun stuff. It's Blue RASPberry.

                1969 Ford F-250 Camper Special resto project. 390 RV cam, Demon carb, Sanderson headers, 2 and a quarter pipes with Magnaflow mufflers. It's Blue Jay.

                Comment


                • #9
                  Sounds pretty

                  close to what I'm doing with the 16 inch rear wheels. Not sure if you have a standard or not.
                  mack
                  79 XS 1100 SF Special
                  HERMES
                  original owner
                  http://i946.photobucket.com/albums/a...ps6932d5df.jpg

                  81 XS 1100 LH MNS
                  SPICA
                  http://i946.photobucket.com/albums/ad305/mack-055/2.jpg

                  78 XS 11E
                  IOTA
                  https://youtu.be/wB5Jfbp6SUc
                  https://youtu.be/RaI3WYHSuWA



                  Have recovery trailer and shop if you breakdown in my area.
                  Frankford, Ont, Canada
                  613-398-6186

                  Comment


                  • #10
                    SG, no-mods.
                    1990 Ninja ZX-10. It's the Silver Surfer. HI-YA!!

                    2006 Yamaha XT-225. Yep, I take it on the interstate. It's Blue Butt.

                    1982 Toyota 4x4. 22R Cammed, 38/38, 2" pipe, 20R head with OS valves, performance grind and other fun stuff. It's Blue RASPberry.

                    1969 Ford F-250 Camper Special resto project. 390 RV cam, Demon carb, Sanderson headers, 2 and a quarter pipes with Magnaflow mufflers. It's Blue Jay.

                    Comment


                    • #11
                      That rpm sounds about right. Size and shape of front tire will change speed readings too. Running a 110.90/19 on mine corrected a 5 mph fast error on the speedo. Regardless, your tach is in the ballpark for sure with those numbers.
                      1980 XS 11 Special: The King of Kong, 9th wonder of the world. Pacifico fairing, chopped shield, Yamaha hard bags, Diamond seat, T-Kat fork brace, XJ top end, YICS Eliminator, '80 carbs from Spyder Cycle Works, K&N Air filter, Fuse block, stainless steel valves & reg/rect from Oregon MC Parts. Raptor CCT, XJ air shocks, 850 FD, Sportster mufflers, Standard handle bar, Tusk Bar Risers, SS braided brake lines. Cat Eye speedometer. HID projector beam headlight, LED running lights.

                      Comment

                      Working...
                      X