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Thread: Q: Bevelhead Ducati. How to free-up a binding clutch?

  1. #1
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    Q: Bevelhead Ducati. How to free-up a binding clutch?

    Ok, I'll be the first to admit it: The MHR does not get enough riding.

    Aside from a WoF and new a front tyre there isn't actually much holding it back.

    Except the clutch - which is binding (again).

    I've pulled it apart before and found parts of it are so polished that with the 50 weight oil they virtually vacuum themselves together.

    So whats the recommended cleaning and loosening treatment for a ducati clutch, and do I rough it up a little with some steel wool or something?

    Cheers,

    Jim
    =mjc=
    .

  2. #2
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    3rd October 2006 - 21:21
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    Not too badly notched into the fingers of the clutch basket?
    On that, I remember mine being a basket! Hard to find N at the lights and very heavy.
    Only a Rat can win a Rat Race!

  3. #3
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    28th January 2015 - 16:17
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    +1 - have a look at notching. The basket is likeliest but also check the hub. Frictions and steels should be able to slide axially on both without interference. Also worth checking for sharp edges on steels, if these are digging in on hub splines then that can be part of the problem.

    Something worth a look at is release travel. I found on the dry clutches that owing to plates being a bit springy and not perfectly flat, that around 2mm of clutch actuator travel was needed to get them to release properly. On that note... check your pressure plate for cracking. If its similar to the high zinc alloy found on the belt drive bikes then it'll be cracked after mileage and will be flexing badly under load, ie not releasing properly.

    Polished surfaces locking up under oil isn't one I've dealt with before (dry clutches only on both my bikes) so pinch of salt here - maybe put the steels onto a flat plate, with some 160-grit paper down, and lightly rough them, taking care to rotate every once in a while so you get even coverage?
    Last edited by OddDuck; 23rd September 2019 at 20:32. Reason: Actuator travel and pressure plate cracks, added in later

  4. #4
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    What they said.
    How old are the drive plates?
    You can get a longer actuator ( lever that sticks out top of rh cover or as I did convert a ducati belter clutch ( you can buy custom ones but 500 us from memory)
    Levels are not known for ease of finding neutral.
    They however are fun to ride and sound great

    Unrelated but replaced the old friction plates in my Commando and it transformed it, light, no drag, readier gear changes.
    DeMyer's Laws - an argument that consists primarily of rambling quotes isn't worth bothering with.

  5. #5
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    Front wheel against a wall, 4000rpm, clutch in and Slam it into gear and . . . .




    it was just a suggestion
    I've been told. Dreaming`s free.
    Think I'll go, back to sleep.
    Everybody listen, voices in my head
    Everybody listen, do yours say, what mine says?

  6. #6
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    Quote Originally Posted by F5 Dave View Post
    Front wheel against a wall, 4000rpm, clutch in and Slam it into gear and . . . .




    it was just a suggestion
    .... ran when parked up, may need gearbox work due to bodgy repairs by previous owner ( see above)
    DeMyer's Laws - an argument that consists primarily of rambling quotes isn't worth bothering with.

  7. #7
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    Hey cheers for the input lads.

    Hope to get that clutch sorted this weekend.

    "glazed" was the word I was thinking of...
    =mjc=
    .

  8. #8
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    Quote Originally Posted by jim.cox View Post
    and do I rough it up a little with some steel wool or something?
    I always used to bead blast steel plates in any clutch I had apart
    "If you can make black marks on a straight from the time you turn out of a corner until the braking point of the next turn, then you have enough power."


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  9. #9
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    I find real smooth flat concrete and figure 8 the steels. Then brakeclean.
    I've been told. Dreaming`s free.
    Think I'll go, back to sleep.
    Everybody listen, voices in my head
    Everybody listen, do yours say, what mine says?

  10. #10
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    8th February 2018 - 20:43
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    I imagine the clutch is the same as the Darmah?
    From memory, my Darmah had about an 8 piece push rod (including balls)- I had all sorts of issues until I replaced it with a 2 piece rod with 1 ball between rods, as the drilling between crankcase halves wasn't straight! Maybe Ducati only had short drill bits when they were building these motors?
    I also converted it to hydraulic operation using a complete VT250 Honda setup. Took about an afternoon- I replaced the LH original cover with a piece of Ally (10mm) to mount the slave cyl on. Worked a treat and never had any more issues with it.
    Remember when I sold the bike, I got all the 'experts' commenting on the conversion!! Bloody wankers.

  11. #11
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    "Bother!", said Pooh.

    Well, that hasn't gone so well...

    The previous weekend I stripped, cleaned and repacked the clutch. Nearly, but not oh so not quite, got her running.

    This past weekend I drained the tank and cleaned taps and lines.

    I kicked her over - and found that when I put her in first, even with the clutch pulled in, the engine is trying to turn over...
    =mjc=
    .

  12. #12
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    That makes little sense, or rather I don't understand.

    So later ducs were dry clutch, these are wet yeah? There will be a decent amount of drag when it is cold and in gear.

    I'd warm it up nicely and try again.

    Failing that take it for a ride crash starting it, ride it and see if the clutch is freeing.

    So when you rebuilt it did you try pull the clutch and see that it rotates? if you can do that with cover off, I'm presuming a far side pushrod rather than a near side pull .
    Did the pressure plate move ok?
    I've been told. Dreaming`s free.
    Think I'll go, back to sleep.
    Everybody listen, voices in my head
    Everybody listen, do yours say, what mine says?

  13. #13
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    Quote Originally Posted by F5 Dave View Post
    That makes little sense, or rather I don't understand.
    Yeah, that's what I said.


    Quote Originally Posted by F5 Dave View Post
    So later ducs were dry clutch, these are wet yeah? There will be a decent amount of drag when it is cold and in gear.
    Yes, wet clutch same as 900SS and Darmah.

    They are a heavy clutch, but I would have thought that I should be able to push the bike in 1st, clutch in and not being turning over the motor against the compression.

    At the lever the clutch feels normal, and the whole shebang does move. But I like the idea of checking and lubing and the actuation rods, it must be 20 yrs since I was last in there


    Quote Originally Posted by F5 Dave View Post
    I'd warm it up nicely and try again.
    That was my thinking. Pumping some warm oil over those fresh plates may well help.


    Quote Originally Posted by F5 Dave View Post
    Failing that take it for a ride crash starting it, ride it and see if the clutch is freeing.
    Got to get her started first...

    Quote Originally Posted by F5 Dave View Post
    So when you rebuilt it did you try pull the clutch and see that it rotates? if you can do that with cover off, I'm presuming a far side pushrod rather than a near side pull .
    Did the pressure plate move ok?
    Yes to the above, but I did note the pressure plates seem worn at maybe 3.6 - 4mm thick. That I would have expected that would lead to slippage, not locking up.

    Nevermind, I'll try kicking her in guts again this weekend...
    =mjc=
    .

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