1996 1200cc Daytona - Clutch Slipping When Hot

Discussion in 'Technical Help' started by MikeD, Aug 8, 2020.

  1. MikeD

    MikeD Member

    Jul 1, 2020
    36
    13
    Mechelen
    Hi Everybody,

    A problem occurred on my 1996 1200cc Daytona today, which I would really appreciate any and all advice.

    I was driving on the motorway, doing around 130 Km/hr (80mph) , around 4000 revs, cruising nicely, when the revs suddenly shot up to 6000

    I immediately pulled off the motorway, stopped, couldn´t spot anything obvious, then was able to continue at around 60Km/hr (40mph) ... as I continue to ride the clutch started to slip again ... to the point when I couldn´t even pull away in 1st from a standing start

    I let the bike cool down for 45min, then was able to ride again , but only for around 2Km ... when, again, I couldn´t even pull away from a standing start

    I phoned Breakdown Recovery and the bike is now back home.

    It appears that something is causing the hydraulically operated clutch to slip when it gets hot

    All advice is welcome

    Cheers

    Mike
     
  2. stevethegoolie

    stevethegoolie Elite Member

    Oct 16, 2014
    2,454
    800
    East Riding of Yorkshire
    Just checked the infamous Haynes manual of fairy tales, lies and wizardry which gives several causes of clutch slip ....

    Clutch master cylinder reservoir fluid level too high.
    Friction plates worn or warped.
    Plain plates warped.
    Clutch springs broken or weak.
    Clutch centre or outer drum unevenly warn causing improper engagement of the plates.

    It would appear that, if what the Haynes manual says is correct - and let's face it it probably will be - then you will more than likely be in need of a new set of clutch plates and springs.
    No mention is made of the slave cylinder or the pushrod that it acts on.
    If it helps, my '95 Trident 900 has just short of 56,000 miles on the clock with no clutch problems so far - tempting fate, I know! How that compares to your Daytona only you will know.

    Just an afterthought ... are you running it on proper motorcycle oil and not car oil? Car oil is not designed for wet clutches and can cause them to slip due to friction reducers in the oil. Apparently it doesn't always cause slip - as some on here have previously experienced - but it could be another cause.

    Good look with it.
     
  3. MikeD

    MikeD Member

    Jul 1, 2020
    36
    13
    Mechelen
    Hi Steve,

    Thanks for your reply and ideas

    The thing with the first 5x possible causes which you have listed, is that surely they would also cause the clutch to slip when the engine is cold/cool ... which is not the case with my bike

    There is car oil in the engine. I will try replacing that for starters. Hope that is the cheap (stupid) solution

    All the best

    Mike
     
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  4. Rocker

    Rocker Elite Member

    May 1, 2016
    1,662
    800
    Suffolk
    Too much fluid in the master reservoir will only be a problem when hot
    Check that first :) due to expansion
    The bike v car oil is another debate with many using it with no ill effect
     
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  5. MikeD

    MikeD Member

    Jul 1, 2020
    36
    13
    Mechelen
    Hi there - the clutch fluid is mid-way between the high and low limits - so I think I can rule that out - though I like the theory - is there anything else you can think of that would result in the build up of clutch fluid pressure in the system? - Thanks
     
  6. Rocker

    Rocker Elite Member

    May 1, 2016
    1,662
    800
    Suffolk
    I have owned a nineties Daytona but not 100 percent up on the clutch operation or adjustments may as Steve said it's just time for a new clutch but only way to find out is take her apart
    Not a difficult job and then you'll know
     
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  7. Callumity

    Callumity Elite Member

    Feb 25, 2017
    3,358
    800
    Nr Biggar
    Car oil lubricates a bike engine perfectly well but the engine isn’t the issue. Bikes share engine AND gearbox oil so the friction modifiers used in car oil to minimise metal to metal contact in thin oil will affect clutch plate friction. The oil gets thinner as it gets hotter which is fine for mechanical efficiency and emissions reduction but worse for a multi plate wet clutch and the older the clutch........
     
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  8. MikeD

    MikeD Member

    Jul 1, 2020
    36
    13
    Mechelen
    Hi there,

    Thanks for your info. I think I must have the wrong oil. It is at least worth a try, before I go dismantling the clutch assy. Do you think it will be OK to drain the current oil, change the filter, and install good oil ... or do I need to, somehow, clean the current oil from the clutch plates?
     
  9. Callumity

    Callumity Elite Member

    Feb 25, 2017
    3,358
    800
    Nr Biggar
    Just do a simple oil change. It will massively dilute and displace any residual car oil. If it doesn’t work then you know you need new clutch plates and probably springs but the chances are pretty good that it will fix the problem.
     
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  10. MikeD

    MikeD Member

    Jul 1, 2020
    36
    13
    Mechelen
    OK, I´ll give it a wizz. Will let you know the outcome
     
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  11. XCaTel

    XCaTel Senior Member

    Feb 22, 2018
    511
    143
    Ireland
    How did it go Mike?
     
  12. XCaTel

    XCaTel Senior Member

    Feb 22, 2018
    511
    143
    Ireland
    How did it go Mike?
     
  13. Callumity

    Callumity Elite Member

    Feb 25, 2017
    3,358
    800
    Nr Biggar
    Embarrassed silence. Oil. :joy:
     
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  14. MikeD

    MikeD Member

    Jul 1, 2020
    36
    13
    Mechelen
    Hi there. I started by replacing the oil, but that alone didn’t fix the problem ... in the primary clutch fluid reservoir, there are two holes: one for feeding fresh fluid into the system: and a 2nd; very small, pressure relief hole - this one was blocked, so as the fluid heated up and expanded, the increase in pressure wouldn't vent and disengaged the clutch plate instead .... fixed now. Thanks All for the help and suggestions.
     
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  15. XCaTel

    XCaTel Senior Member

    Feb 22, 2018
    511
    143
    Ireland
    Wow, nice catch Mike, who would of thought? Thanks for posting.
     
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