r100gs clutch slipping

Discussion in 'Airheads' started by pecos, Jan 7, 2013.

  1. pecos

    pecos BAM!!

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    When I shift into first to get the bike going, works fine. After I am moving and its time to shift to second, it feels like the bike is winding up and not engaging. Like RPMs increase when giving throttle but not grabbing like it should. Same for third.

    I am guessing the clutch is worn out? Why wouldn't this happen in 1st gear?
    #1
  2. Airhead Wrangler

    Airhead Wrangler Long timer

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    1st gear loads the clutch the least due to the mechanical advantage of the gearing. Each gear higher loads the clutch a bit more. Check your clutch cable to make sure the clutch has adequate freeplay when fully released. Make sure there are no signs that the clutch has been contaminated with oil because of a failed rear main seal or input shaft seal.
    #2
  3. pecos

    pecos BAM!!

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    Just called my old man. He said the same thing about loading the clutch with each gear. Poo Poo Ka-Chu.
    #3
  4. Airhead Wrangler

    Airhead Wrangler Long timer

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    Then your old man knows a thing or two. :D

    I'd guess the cable is out of adjustment. Even if your clutch is drenched in oil, it usually won't slip until third or fourth gear. Try putting more slack in your clutch cable and I bet it'll start behaving. I believe the correct spec is 2mm of free play at the lever before it makes contact with the pushrod. There's also a spec for cable length from the cable stop to the lever on the back of the trans, but to me it doesn't matter much as long as there is free play.
    #4
  5. pecos

    pecos BAM!!

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    Yes, he is a master mechanic that I occasionally get a long with. I thought there was rather a lot of slack in the lever. Will mess with it a little more.
    #5
  6. disston

    disston ShadeTreeExpert

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    There are two levers. Too much slack in the handlebar lever is not going to help because the clutch throw out arm on the trans is probably too tight to make up for it.

    Look at the arm at the other end of the clutch cable on the back of the transmission. There is a bolt adjustment on this arm and a nut to lock the arm. This arm should have free play. It should move easily when moved forward until it is perpendicular to the rear of the trans. At this point you will not be able to move it easily by hand.

    All of this we are saying to encourage you to take an interest in the things that make up the systems on your motorcycle. The clutch has a specific adjustment and if not right they do not work right and they will wear out prematurely. You may get lucky and be able to set the adjustment and it will work fine. But about half the time we hear this same complaint here the clutch is in need of major surgery.

    Further instructions for adjusting clutch levers, arms and cables will be found in your workshop manual.
    #6
  7. pecos

    pecos BAM!!

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    Made the adjustments and still slips. Time to open it up.
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  8. ignatz72

    ignatz72 call me iggy

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    What about checking the throwout bearing and bore? Sure is easier than a full tranny/clutch pull-down.
    #8
  9. craydds

    craydds Long timer

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    Pecos, double check everything externally - clutch lever, cable, throwout bearing/assembly, etc. As disston said, there is a correct clutch adjustment, see post #114 here http://www.advrider.com/forums/showthread.php?t=848159&page=8 , and as ignatz72 says, check your throwout mechanism, see post #101 here http://www.advrider.com/forums/showthread.php?t=848159&page=7 . Clutches do wear out but often times just cleaning, lubricating, and correctly adjusting will keep these old bikes running strong.
    #9
  10. craydds

    craydds Long timer

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    That spec is 201 mm, and it DOES matter. If this is not in spec the earth will cease to rotate about its axis. Seriously, set it to 201 mm FIRST, then adjust the freeplay with the throwout bolt.
    #10
  11. disston

    disston ShadeTreeExpert

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    As mentioned by Ignatz72 there is a recurring problem with the throw out bearings. I don't have one of these, mine is the older system. But the throw outs were made of metal and later plastic. They were multi piece and later they were a single piece design. The throw out bearing is inside the rear cover. It can expand with heat and can get stuck in the bore so I think this could cause the clutch spring to not release.

    [​IMG]

    The parts fiche shows it as two pieces but if you buy a new one it is one piece.

    I hope I got this right but I don't have one.
    #11