four hundred four strangeness

Discussion in 'Classic Motorbikes' started by mark, Nov 22, 2008.

  1. mark

    mark Guest

    When I make off in a spirited fashion something happens clutchward.
    It feels like a small wheel spin as if the back wheel was on some
    gravel.
    Happens occasionally when changing gear and accelerating hard.
    Clutch adjustment seems to be OK.

    ?
     
    mark, Nov 22, 2008
    #1
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  2. The clutch is knackered and slipping. Replace springs and plates - cost
    about £50.
     
    The Older Gentleman, Nov 22, 2008
    #2
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  3. mark

    mark Guest

    Hmm bits seem to come to twice that at Dave Silvers but looks simple
    enough to do.
    Any gotchas?
     
    mark, Nov 23, 2008
    #3
  4. mark

    mark Guest

    Bad form etc
    ebc are about 50 quid...
     
    mark, Nov 23, 2008
    #4
  5. That's what I was thinking of. You could compromise with OE springs and
    pattern plates, but I've used pattern clutch kits before and never had a
    problem.

    The very important thing is to remember to soak the friction plates in
    clean engine oil for an hour or two before you instal them.

    And, obviously, note the order in which the steel friction and the fibre
    friction plates are stacked. Dont get this wrong!

    When undoing and doing up the four bolts that hold the plates in, loosen
    each screw a little, working diagonally, so undoing them evenly. Don't
    just undo one totally, and move onto the next: it'll put a lot of strain
    on the last one and the post it goes into could snap. Similarly, when
    re-fitting, tighten them all up diagonally, a little at a time.

    Easy job, really.
     
    The Older Gentleman, Nov 23, 2008
    #5
  6. mark

    mark Guest

    Ta.
    I've never replaced a clutch before so any advice is welcome :)
    I have been carefully studying the pictures in the venerable Clymer that
    came with the bike. I'm assuming its rare for the metal plates to need
    replacing?
    I shall report back on the 'easy' factor :)
    It'll have to wait for a little while; apparently we need a wood
    burner...............................
     
    mark, Nov 23, 2008
    #6
  7. Very rare. Only happens when the clutch has been so abused they've
    turned blue and warped, and that really isn't likely on a
    ShiteOld400Four.
     
    The Older Gentleman, Nov 23, 2008
    #7
  8. mark

    Pete Fisher Guest

    Perhaps TOG is thinking of the days of cork insert friction plates? As
    far as I am concerned a quick wipe with an oily rag suffices (though not
    on a dry clutch naturally).

    --
    +----------------------------------------------------------------+
    | Pete Fisher at Home: |
    | Voxan Roadster Gilera Nordwest * 2 Yamaha WR250Z |
    | Gilera GFR * 2 Moto Morini 2C/375 Morini 350 "Forgotten Error" |
    +----------------------------------------------------------------+
     
    Pete Fisher, Nov 24, 2008
    #8
  9. I thought it was common knowledge. It allows them to soak up the oil -
    remember they're essentially fibre, and if they're totally dry, the
    clutch may grab.

    That said, putting them in dry and then running the engine for a
    short while will probably have the same effect.
     
    [email protected], Nov 24, 2008
    #9
  10. mark

    Rich B Guest

    [email protected] typed:
    Cork plates, definitely. I can't see why modern fibre plates should be, but
    then it's recommended practice for Land Rover Railko bushes as well, and
    they would seem to be impervious material. Perhaps it's magic.

    --
    Rich B

    1971 S2a
    1995 XT600E
    2003 ST1300 Pan European
    Oh, and a Ford

    Take out the obvious to email me.
     
    Rich B, Nov 24, 2008
    #10
  11. mark

    Pip Luscher Guest

    I've read it somewhere as part of assembly instructions, it might have
    been instructions that came with a set of plates and I've heard of
    others doing it.

    I'm not absolutely certain why it was considered necessary, though I
    have a vague idea it's to do with clutch life. I suppose that if the
    engine were left a while before being started, you'd get plates that
    were half oiled and maybe you could get a juddery clutch action, but
    that's only a guess.
     
    Pip Luscher, Nov 24, 2008
    #11
  12. mark

    Pete Fisher Guest

    Oh, yes, oil the surfaces of them by all means, but I don't understand
    the need for a prolonged soak of modern friction materials. I suppose if
    you had done the job as part of an engine out rebuild it might be
    important, but as a fix the clutch then immediately see if your fixing
    has worked job I can't see the need.


    --
    +----------------------------------------------------------------+
    | Pete Fisher at Home: |
    | Voxan Roadster Gilera Nordwest * 2 Yamaha WR250Z |
    | Gilera GFR * 2 Moto Morini 2C/375 Morini 350 "Forgotten Error" |
    +----------------------------------------------------------------+
     
    Pete Fisher, Nov 24, 2008
    #12
  13. mark

    mark Guest

    It seems the ebc items are cork based...
     
    mark, Nov 24, 2008
    #13
  14. mark

    sweller Guest

    Neither have I and I've never done it.

    When we (read: Mike) changed the clutch on the race bike they were just
    put in.
     
    sweller, Nov 24, 2008
    #14
  15. mark

    Pip Luscher Guest

    Oh, only for a brand-new clutch. I did Google this and someone
    mentioned plates swelling as the oil soaked in as a possibility.

    I'm sure I saw it somewhere that had some authority (to me at the
    time), though I suppose it could've been a HBoL.

    I have assembled new clutches before I heard about having to soak them
    and had no problems; I've also 'soaked' them for about 10 mins, again
    without problems, so maybe it is just a hang-over from ye olden days.
     
    Pip Luscher, Nov 24, 2008
    #15
  16. mark

    Rusty_Hinge Guest

    The message <>
    I think those Lard Roller bushes are sintered phosphor bronze, or
    similar, and if so, will be very slightly porous.

    BTW, don't use Hipoy or similar on Oil-Lite bushes - Mk I Concertinas
    has them in their gearbrokes, Glod knows why - and they un-sintered...
     
    Rusty_Hinge, Nov 24, 2008
    #16
  17. mark

    Rusty_Hinge Guest

    Can't do any harm, in any event.
     
    Rusty_Hinge, Nov 24, 2008
    #17
  18. Oh well. I remember reading somewhere it was advisable and so I've
    always done it.

    And guess what? It's always worked ;-)
     
    The Older Gentleman, Nov 24, 2008
    #18
  19. mark

    platypus Guest

    Yeah, but you're getting on a bit.
     
    platypus, Nov 24, 2008
    #19
  20. mark

    platypus Guest

    I used to live next door to a guy who used to build dragsters. He reckoned
    that coating a gasket with grease and leaving it for a while to swell up a
    bit was very effective. It certainly cured the leaky float bowls on the
    R80RT.
     
    platypus, Nov 24, 2008
    #20
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