Kupplung's problem

  • Hallo!
    I've noticed this thing during last ride: as I started the trip, Kupplung's began dragging in a soft and gradual way; after some re-starts (e.g. traffic lights, crossroads), dragging began to be more and more sudden, almost an on/off Kupplung. Engine stopped sometime too while re-starting :(


    Do you think Kupplung plates have to be replaced? (or, at least the friction ones, leaving the plain ones as they are)


    Remark: I don't know how old the plates are, they could be the same Yamaha installed in 1981 if previous owner didn't replace.
    And: some time in the past I've had to unstick them because of long non-working time, worked it out simply by putting the bike on central stand, starting the engine, 5th gear in, disengaging the clutch and accelerating while braking with pedal; maybe plates are not at their 100%.


    Grüßen :ber:


    Simone

  • Also:
    short time ago someone complained a sticking clutch.
    It was due to gear oil with too high viscosity.
    Sometimes the clutch adjustion is too narrow.
    The pressure Point should be parallel to the Alu-mark at the housing.
    Regards
    Rei97

  • Look for the Bowden cable, the clutch disces are very strong, I`ve never heard of any changing at least 80000 km.
    zechstein

    Das Gute, das steht nun fest,
    ist das Böse, das man lässt.
    W. Busch

  • Zitat

    Original von Zechstein
    Look for the Bowden cable, the clutch disces are very strong, I`ve never heard of any changing at least 80000 km.
    zechstein


    I think equally....

  • Thanks everybody for answering! :)


    @ rei97: the oil I use is a good old Mineralisches 20W-50, I don't think the problem is related to it. For the pushrod's pressure point, I checked its alignment just on Saturday morning before starting and everything looked OK.


    @ Zechstein & barnix: I'll take a further look as soon as possible, but as I remember the cable didn't play tricks (e.g. no sticking or jerking along). I lubricated it well in last August while I was on holiday.


    I'll keep you updated.


    Grüßen :ber:


    Simone

  • Update: the Kupplung's cable is OK, checked today just before lunch.


    I've dismantled the pushrod's cam too, and I've seen that there's a little wear notch just where it... pushes the pushrod. (Just like the one that can be seen here in "Der Knebel" photo.)
    There was another little wear sign on the Einstellschraube. I think that those two "wear signs" put together have busted the regulation I made on Saturday morning... or maybe I did an uncorrect regulation at all.


    I've then tried to re-regulate the cam, but I've seen that the only way I had to achieve a perfect parallelism with the housing's mark was to fully screw in the Einstellschraube. (Anyway I've not screwed it thoroughly because, doing so, it presses against the cam's body: I guess something could get damaged during operating in such conditions.)
    I've had no time today to get te bike on the road to try, I hope to do it ASAP.


    I'll keep you updated. Grüßen :ber:


    Simone

  • Zitat

    Original von Muffler82
    ... I guess something could get damaged during operating in such conditions.


    Simone


    Hallo Muffler92,
    I would agree witch you, you mutsn´t screw in against the resistance. That would quiet shurely damage the Gewinde inside the block. Repairing this is (my experiance) not quiet easy.
    Because of this (when I understand you well) sudden effekt, I first would think about a damaged clutch-kabel, too.
    The pitting marks on the abjusting parts (left side) are, I believe, normal use-marks after this long time (since 1981)
    Maybe you also check the two needle-bearings of the adjust-Hebel


    good luck


    lindi


  • Hallo Lindi,
    The cable looks OK; the cam's two Nadellagern looked all right too, I've checked yesterday after dismantling the cam (I found a very little play between them and the cam's body).


    Grüßen :ber:


    Simone

  • Update:
    Have tried the bike on this morning, nothing doing, although all the regulations.
    It's gradual at the beginning and then more and more sudden, like it did last time. (By the way, I've had to unstick plates again, despite less than 7 days since last ride :()
    Sometime I've noticed that gear changes were noisy and jerky, too.


    I'll took off clutch cover on tomorrow (after watching MotoGP race :)) to take a closer look, also at the parts arrowed by Zechstein and Hetzer.


    Grüßen :ber:


    Simone

  • Here I am...
    I've dismantled the crankcase cover in the morning to take a look to the clutch. I know I had to do it on last Sunday, but since Saturday evening I'm wrestling with a cold, cough and sore throat - and consequently with a carriage of antibiotics :(


    Anyway. Here's the situation:
    Springs length: new 41.2 mm, measured 40.9;
    "Driven" plates: nearly mint conditions;
    Friction plates thickness: new 2.8 mm, measured 2.7 - 2.8 (each plate's been measured in 4 points), but they're completely vitrified.


    I've already ordered a kit of new friction plates + new springs (I'll replace them too, even if they don't need to, and I'll keep the "old" ones as emergency spare). I hope it will arrive soon, obviously :)


    Grüßen :ber:


    Simone

  • hi,
    i'd start from the very top:
    Is the clutch lever working without wear?
    Does the cable show any signs of wear/cranking/breakage?
    Can You feel any loseness while pulling the clutch?
    How about the Clutch lever on top of the engine housing? Synchronosity in operation with the hand-lever?
    SR-clutches itself are quite hard to boil/waste/wreck.
    All the right tools at your hands!
    Claus

  • Hi,
    what`s going on with your clutch?
    Grüssen
    Zechstein

    Das Gute, das steht nun fest,
    ist das Böse, das man lässt.
    W. Busch

  • Hallo,
    No news about the clutch unfortunately. :( But in the meanwhile I've cut out a new gasket for the sump (this doesn't relate at all with the clutch question, but it's to show that I'm not sitting on my hands :D hehehe)


    Grüßen :ber:


    Simone

  • You should disassemble the clutch, clean the plates with Kerosene, Petroleum, Gasolio oder Brakleen, and rub them carefully with a brass-wire-brush. If the steel plates are blueish or torn, you should change them. I roughen the steel plates with a flat file (you should know what you are doing...) or sligthly with a flex while letting rotate them slowly in a lathe.
    While the Clutch is opened, retigthen the central nut and check the Kupplungsdruckstange if both tips ar round and without wear.



    Gruß
    Hans

  • Thanks for suggestions Hiha, I've checked steel plates when I dismantled the Kupplung and they looked almost like new, there were no damage signs. Do you suggest to rough the steel plates anyway (e.g. to help preventing future sticking)?


    News: cover's gasket and 6 new springs have arrived in the evening (at last!) but friction plates haven't yet. :a:


    Question about springs: both old and new ones have half of the outer surface covered with a white patina, it looks like varnish. On old springs, you can take it away by simply scraping it with a nail.
    Is that "varnish" to be cleaned away from springs before installing?


    Grüßen :ber:


    Simone

  • Ciao Simone,


    Zitat

    Original von Muffler82
    Do you suggest to rough the steel plates anyway (e.g. to help preventing future sticking)?


    Yes. :)

    Zitat


    Is that "varnish" to be cleaned away from springs before installing?


    You can leave it, but I would clean the springs, if it is not too much action.



    Hans


  • Perfect, thanks for suggestions.
    I'd like to use sandpaper to rough steel plates (tricky work using the file, and I haven't got a lathe...): which kind do you think is better to use? A fine or a coarse one?


    P.S. friction plates are finally arrived! :) Now they're sitting in oil after a good cleaning, before installing...


    Grüßen :ber:


    Simone

  • Update.
    Clutch is installed; plates seem to stick a little bit again after the bike has been resting for some time, but I've simply freed them by moving the bike with GIPC (gear in and pulled clutch :)).
    I think things can't go a lot better with wet clutch and 20W50 oil...
    I've had no time to try it on the road at the moment. :(


    Grüßen :ber:


    Simone

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