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  • Chain Tensioner

    Hi,
    Cut from 10mm chopping board a round chain tensioner.
    Before I drill the inner casing, is it a good idea ????
    I was going to seal and bolt it up, to take some slack out, as the chain is not that old. ( sure someone will say put a new one in. ) But has stretched a bit.
    Also some chain wear on the outer cover at the bottom.
    The mainshaft ???? that hold the clutch basket, moves in and out 2mm maybe 2.5mm.
    What needs shiming, adjusting to take this play out, or is it ok ????
    Thanks for the replies.

    whitehillbillies
    Attached Files

  • #2
    I've used this idea in the past (and plan to with my TFS). I cut a piece the right thickness off a piece of nylon bar. Easy enough to turn down to get the right diameter.

    One thing you're missing. Your design has no means of adjustment when the primary chain stretches, which it will.

    If you drill the fixing hole in the nylon disc off-centre, it then mounts eccentrically, which means you can rotate it to tighten the chain.

    Bolt it tight, direct to the chaincase backplate. There is no need for it to rotate.

    If you mount it so that the direction of the chain run tends to try to rotate it "tighter", there is no way it will loosen. You'll need to use the lower chain run of course.

    I hope that bit's clear - if not I'll do a drawing.

    The bottom line is: it works!
    Colin Sparrow

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    • #3
      Thanks Colin.
      I have the old type, multi size hole saw with the drill bit in the middle, hence the middle hole.
      I was not so worried about a tightening one with the off set hole, just figure when it gets loose again, its time to put in a new chain.
      Or maybe I can drill a M6 hole offset and sill use it.
      More just to remove the whip on the slack side.
      I removed the cover to add the 6 new weaker springs from Villiers Services, to try and lighten the clutch a bit.
      Saw this one, maybe yours a while back and liked the idea.
      Thoughts on the mainshaft ? play.

      whitehillbilly
      Attached Files
      Last edited by whitehillbillies; 18/09/2016, 09:20 AM.

      Comment


      • #4
        Had I look in my books and wonder If I have some movement in my bearing behind the gearbox sprocket.
        It was fitted to its housing with a Loctite product when I rebuilt it, as it wasn't a tight fit.
        Don't want to pull the box apart yet.
        would have had the correct mainshaft clearance when rebuilt.
        2mm seems a lot to gain.

        whitehillbilly

        Comment


        • #5
          For those that are not so mechanical Villiers Services do one

          Comment


          • #6
            Tony, what holds the VS one in place? Looks like it might save drilling a hole in the back plate?

            The last hillbilly photo is what I was talking about - although it's not one I did. The idea came to me years ago from former committee member Adrian Thomas.

            Do you mean you have 2mm of play in the drive side mainshaft bearing? Not an expert, but that's far too much, surely?
            Last edited by Colin Sparrow; 19/09/2016, 09:27 AM. Reason: More thoughts added
            Colin Sparrow

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            • #7
              Hi Colin,
              The drain plug has an extended lug, which fits up inside.
              That is what holds it in.
              No holes to drill, fits straight to chain case.
              Just drain oil, remove outer cover, then put in adjuster, add new extended drain plug, outer cover on and refill with oil.
              Not sure of the purpose of the two holes. Spring holds the chain tight.
              Yes 2mm of play, but don't know where the play is.
              Thanks.

              whitehillbilly

              Comment


              • #8
                The 2 holes may have been machined early on in the machining stage to take 2 retaining pins which hold the plastic block in place during the machining of the block profile. Have you checked that the clutch hub centre nut is still tight? Just looked at a spare gearbox and it has just over 1mm end float approx. A possible cause of excessive end float could be the bush on the non drive end of the mainshaft, in the right hand gearbox cover. May be worth checking the oil for bronze particles.

                Comment


                • #9
                  Originally posted by tony View Post
                  For those that are not so mechanical Villiers Services do one

                  We use to use something very similar when I raced karts with the 210cc villiers engine.

                  Comment


                  • #10
                    Measured the main shaft endfloat with my dial gauge.
                    Got 1.2 mm,
                    So similar to floydbassman's spare box.
                    I have some graphite Grease for the thin brass disk.
                    Do you need to Grease the loose roller bearings, before fitting them to the clutch basket ?
                    While since I have done it.

                    Whitehillbilly

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                    • #11
                      I always grease the rollers when assembling the clutch basket.Apart from lubricating, it holds the rollers in place when assembling. Its amazing how much abuse the clutch assembly can take. When I first got my TFS back in 72, it had no chaincases fitted and I rode through all sorts of mud and streams when using it as a field hack at the age of 12! the only thing that did suffer wasw my left boot with frequent encounters with the exposed primary drive...

                      Comment


                      • #12
                        Had a good chat with leus, at Villiers Services tonite.
                        Very helpful with my 1.2 mm mainshaft Play.
                        Suggested replacing the mainshaft Bush, in the gearbox cover. E.8410
                        The pressure washer. E.8541.
                        Ball bearings 3/16 dia (14) E.9775
                        Then adjust with shim washers. E.7347
                        Aiming around 10 thou imperial end float.
                        Look at ordering parts in a day or two.
                        Thanks for the input.

                        Whitehillbilly

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