Clutch fix/problem

Discussion in 'Dakar champion (950/990)' started by KTMROB, May 31, 2004.

  1. KTMROB

    KTMROB Been here awhile

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    The clutch on my 950 spat the dummy on the weekend. I read the Jean Luc account of his problem and mine was identical. Started losing pressure at the lever until there was none. Pumping the lever brought the pressure back momentarily until I couldn't get any clutch action at all. The upside was this was on a KTM dealer ride. They handed over a demo 950 and put mine on their trailer and sent it back to the workshop. The chief mechanic imediatley thought it was the same as similar problems they had encountered. A small o-ring in the slave cylinder has a tendency to get a small nick (cut) in it during installtion due to the edges of the surrounding cast alloy. This nick can then allow air to enter the system. The result being no clutch but still a full or semi full resorvoir. However after pulling the clutch down this ended up not being the problem but rather a small dent/defect in the master cylinder (also a known problem) also allowing air into the system. Hopefully all will be well when its picked up today and I will report further with more precise details of the problem and fix. As a side note I met a number of other 950 riders. One guy had previusly gone over the handlebars at high speed some months ago when mud built up under the front guard which susequently broke with the brake hose catching in the front tyre. As discussed on this board he has modified this by adding a second brake hose. Interestingly this is a pretty cheap fix as the only par required is a longer piece of hose. All the banjos can be rearranged ie left hand caliper fittings up to the handlebar fitting and vice versa. less than $100. This guy is a very impressive rider in the dirt and information from a second source had him timed at a 1.55 sec lap of Phillip Island (MotoGP and World Superbike circuit) on standard Scorpion tyres. Anything under 2.00 on any sportbike is damn good on this circuit. Sorry but I forgot my camera so no pics which is a shame as I saw a new side to this bike in some pretty decent muddy single track terrain.
    #1
  2. claferal

    claferal Been here awhile

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    HI kTMRob,

    Can you tell us if your problem was solved? What is it caused by?

    Thanks
    #2
  3. Jean-Luc

    Jean-Luc Throttle committed

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    Yep, that's exactly what happened to me (you just describe it much better!)
    Similar experience again: they changed mine under warranty.

    That's a great post, thanks for sharing and let us know how it goes.
    #3
  4. KTMROB

    KTMROB Been here awhile

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    All fixed now. I had a look at the master cylinder that was replaced and there was a small scar in the seat where the plunger enters the cylinder. I assume there is a seal in this area. The dealer was great and gave me a 950 loaner for 2 days (practised my ordinary wheelying ability :rofl ).

    Also provided them with copies of the tech bulletins from 950riders.com, which were all attended to. As a side note KTM Australia rang and gave me a bit of hard time for having access to these bulletins. The dealers certainly had never received them!! The guy at KTM wanted the phone number of someone at the website where i located the bulletins :rofl That in itself is a worry.
    #4
  5. Noise

    Noise Dreamy Adventurer

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  6. Noise

    Noise Dreamy Adventurer

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    Good god,

    tell me that this is the solution to the same problem we are having...?

    Greetings,

    Noise Data
    #6
  7. Renegade6

    Renegade6 Been here awhile

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    I believe the tech bulletins came off of the repair manual CD (one that anyone can buy). Instead of worrying about where they came from, they should worry about doing the upgrades before they sell the bikes.

    Had the same problem in the US with the dealers not receiving the bulletins...KTM USA told me that all of the upgrades were done before they were sent to the dealers.
    #7
  8. Jean-Luc

    Jean-Luc Throttle committed

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    Pete,

    Nope, that's another clutch problem that I had in my last ride at the SheetIron. Here they are:
    - initial problem #1 ("our" problem): clutch not disengaging completely. The reason seems to be a lack of lubrification caused by a clogged jet (30 to be replaced by a 50) and by not enough holes on the clutch basket.
    - latest problem (KTMROB and me): no clutch hydraulic pressure despite fluid still on the reservoir. Reason is an air leak either at the slave cylinder (that has to be replaced or if still good at least change the o-ring) or a defect/dent) on the master cylinder.
    #8
  9. KTMROB

    KTMROB Been here awhile

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    My problem was a leak at the master cylinder
    #9
  10. Jean-Luc

    Jean-Luc Throttle committed

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    My bad, you did investigate the slave cylinder BUT it was the master instead. I'll correct my post. Do you have a detailed pic of the "dent" in your mater cylinder?
    #10
  11. KTMROB

    KTMROB Been here awhile

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    It was barely visible to the naked eye. It looked like a whitish crescent shape about 5mm long just inside the side lip of the master cylinder where the clutch is activated by the lever.

    Attached Files:

    • cyl.JPG
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    #11
  12. Greg Minor

    Greg Minor The Trespasser

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    Jean I was tell my shop mecahnic about this and he did not know where the jet is can you give me a discription to give him
    #12