R80GS Basic clutch adjustment question

Discussion in 'Airheads' started by Kokopelli, Apr 13, 2009.

  1. Kokopelli

    Kokopelli Yeah, right!

    Joined:
    May 2, 2003
    Oddometer:
    5,080
    Location:
    Rapaura
    I am now absolutely stumped by this. If I set the measurement 'C' on the diagram to the required 200mm +-1mm I do not get any clutch action, even with the set screw ('4') wound right in. Only at about 190 mm does the clutch work.

    Checked the diaphragm spring against a good one and it's fine. Anyway, the clutch had not been slipping. Tried a completely different clutch, same story. Other than getting quite quick at whipping out the clutch (third time), I've made no progress.

    How can you lose 10mm there? Has the inside of the nylon piston collapsed?

    Should I just ignore it and get on with it?

    [​IMG]
    #1
  2. Sergeant Joe

    Sergeant Joe Sitrep=Snafu

    Joined:
    Mar 8, 2009
    Oddometer:
    244
    Location:
    Tasmania,Australia
    I had to play with the adjuster up on the h/bar leaver as well , its fiddley stuff :tough :baldy .
    #2
  3. Kokopelli

    Kokopelli Yeah, right!

    Joined:
    May 2, 2003
    Oddometer:
    5,080
    Location:
    Rapaura
    I can set it to the 200mm alright, but then it won't disengage the clutch.
    #3
  4. Joerg

    Joerg Long timer

    Joined:
    Jul 10, 2001
    Oddometer:
    1,359
    Location:
    St-George, Switzerland
    Did you proceed precisely according to the rider's manual, i.e. adjust the cluth using both the screws at the handlebar, and the screw/bolt at the back of the gearbox?

    Are you sure the clutch cable is not stuck somewhere (=hull sitting on an edge, etc.) ?
    #4
  5. Kokopelli

    Kokopelli Yeah, right!

    Joined:
    May 2, 2003
    Oddometer:
    5,080
    Location:
    Rapaura
    Yep, It's in properly and I followed the manual. I even used a new clutch cable, it does the the same as the old one, which was still good by the way.
    #5
  6. Joerg

    Joerg Long timer

    Joined:
    Jul 10, 2001
    Oddometer:
    1,359
    Location:
    St-George, Switzerland
    But what did you do before? I mean, the clutch must have worked at some point in time ... ? :lol2
    #6
  7. Kokopelli

    Kokopelli Yeah, right!

    Joined:
    May 2, 2003
    Oddometer:
    5,080
    Location:
    Rapaura
    Good point, it did work. However, I never checked what setting it was on before taking it apart. I had the transmission off to fix a seal. Then decided to check the clutch. Which led to the decision to recondition it. The clutch worked well for 1000km and then the plates stuck together.

    When I had first assembled it after reinstalling the reconditioned clutch I had to wind out the handlebar adjuster pretty much all the way to get the 200mm. After separating the clutch plates again and setting the cable up, I arrived at the current situation.

    I then borrowed a second hand clutch with minimal wear and installed it today, to see if the original clutch resurfacing was to blame. Looks like that wasn't the problem either.

    I don't understand the importance of the 200mm set up. If 190mm will make the clutch work,can I run it like it is now?

    Thanks for your input.
    #7
  8. jtwind

    jtwind Wisconsin Airhead

    Joined:
    Nov 19, 2004
    Oddometer:
    3,477
    Location:
    Madison WI
    I've found that if all parts are right you can play around with the settings to get it to the bmw spec settings. Sometimes you have to move the adjuster on the tranny in or out to allow you to get the barrel adjuster on the lever in the ballpark and vice versa. Why is it important to get it where BMW suggests? Beats me and possibly it isn't. I've always assumed it was due to leverage, clutch pull effort etc.
    #8
  9. Solo Lobo

    Solo Lobo airhead or nothing Supporter

    Joined:
    Mar 16, 2004
    Oddometer:
    10,892
    Location:
    Shoreline, WA
    silly question, did you put the throw-put bearing and push rod back in?

    The manual does say to adjust to the 200mm using the handlebar adjustment and then make the fine adjustment using the trans back bolt...

    Is the handlebar adjuster threaded all the way out?
    #9
  10. AntonLargiader

    AntonLargiader Long timer

    Joined:
    Aug 28, 2003
    Oddometer:
    6,325
    Location:
    Charlottesville, VA
    Just for those who aren't familiar, the handlebar adjuster changes the 201mm. So once that's correct, the hand adjuster is out of the loop. The question is why you can't get proper clutch action with the arm adjuster.

    If the lever is in the right place, and isn't bent, the problem has to be in the TO bearing, pushrod or clutch. If you can only get clutch action with less than 201, then either the lever is bent or something inside is too short.

    Do you have the old-type TOB with the separate parts, or the new one-piece one? Pix on my website: http://www.largiader.com/articles/throwout/

    If something inside is too short, it'll probably keep getting shorter.
    #10
  11. Dolly Sod

    Dolly Sod I want to do right, but not right now

    Joined:
    Aug 18, 2003
    Oddometer:
    18,865
    Location:
    Richmond, Va
    It sounds like you're not adjusting #3 & #4 in your diagram correctly. Once you get the 200mm you should be adjusting #3 & #4.
    #11
  12. Bill Harris

    Bill Harris Confirmed Curmudgeon

    Joined:
    Sep 20, 2008
    Oddometer:
    9,871
    Location:
    backwoods Alabama
    You installed a reconditioned clutch-- what did you do to recondition it? There is a somewhat similar problem being discussed over at Boxerworks after a Southland reconditioned clutch was used:

    http://www.boxerworks.com/phorum/read.php?f=1&i=255039&t=255039

    We still haven't figured this one out.

    Years ago, before the 200+1mm spec was used, the adjustemnt was to set the clutch actuating arm to a right-angle to the clutch pushrod. What sort of angle does the clutch arm amke at the 200mm or the 190 mm setting?
    #12
  13. Kokopelli

    Kokopelli Yeah, right!

    Joined:
    May 2, 2003
    Oddometer:
    5,080
    Location:
    Rapaura
    Thanks for all the responses.

    All the parts are present and accounted for and in the correct order. The lever is not bent. The diaphragm spring is in correctly. The clutch cable has been adjusted as per manual. Once set to 200mm you adjust the free play with the screw adjuster. At 200mm (adjusted at the handlebars) this adjuster does nothing, even wound in all the way.


    I will now substitute the new style assembly with an older version. I suspect the plastic piston with the built in throughout bearing is to blame, even though there is no obvious fault.
    #13
  14. Kokopelli

    Kokopelli Yeah, right!

    Joined:
    May 2, 2003
    Oddometer:
    5,080
    Location:
    Rapaura
    The reconditioned clutch was not the problem, it since been replaced with a standard clutch. The lever is at less than a right angel, it's missing those 10mm. Considering the length of the lever, that's probably only about 2-3 mm at the pressure point. I am almost certain that the problem is with the piston.
    #14
  15. Mista Vern

    Mista Vern Knows all - tells some.

    Joined:
    Dec 1, 2005
    Oddometer:
    22,977
    Location:
    McMinnville, Oregon
    Hail Mary pass here, but are you sure your old TOB didn't go south and thus lead to the push rod being worn shorter? Stupidly long shot, but what the heck, there are only so many possible variables, eh?
    #15
  16. Kokopelli

    Kokopelli Yeah, right!

    Joined:
    May 2, 2003
    Oddometer:
    5,080
    Location:
    Rapaura
    The newer style plastic (nylon, I think) piston has a pretty standard looking bearing, I just remembered that I have pictures :-). The bearing seems fine. The only problem I see is on the other side. Maybe that metal insert got pushed in or is worn out.

    [​IMG]

    [​IMG]
    #16
  17. Solo Lobo

    Solo Lobo airhead or nothing Supporter

    Joined:
    Mar 16, 2004
    Oddometer:
    10,892
    Location:
    Shoreline, WA
    For reference...

    #17
  18. Solo Lobo

    Solo Lobo airhead or nothing Supporter

    Joined:
    Mar 16, 2004
    Oddometer:
    10,892
    Location:
    Shoreline, WA
    #18
  19. Wirespokes

    Wirespokes Beemerholics Anonymous

    Joined:
    Jul 26, 2002
    Oddometer:
    9,599
    Location:
    Jackson's Bottom Oregon
    I'm not sure I completely follow you on this.

    Are you saying that when the arm is adjusted at 200mm, the clutch lever comes all the way back to the grip without releasing the clutch? And that's with the adjuster at the control all the way out?

    I took care of a 100/7 this last weekend with a similar sort of problem. I'm used to setting the arm parallel to the tranny back cover at half stroke, doing that with the adjuster at the trans. Then adjust the hand lever for a few mm of free play. In this case the adjuster was most of the way out to achieve this, which seemed pretty weird. This is a low mile bike (abt 20K) and looked it. The only solution I can come up with is that the cable housing should be longer, or perhaps make the cable shorter.

    Other than that it worked great.

    BTW, don't get fixated on that 200mm setting - the thing to remember is that for ease of pull, the best leverage is achieved when the arm is parallel to the trans at mid pull.
    #19
  20. Kokopelli

    Kokopelli Yeah, right!

    Joined:
    May 2, 2003
    Oddometer:
    5,080
    Location:
    Rapaura
    I am going to install the old style component's as shown on Anton's picture. This should eliminate everything but the user and the clutch cable as being faulty.

    With the lever at at 90 degrees, or parallel to the housing I have my 200 mm. Unfortunately at this stage, even with the screw wound right in I have no pressure against the piston. This tells me that something is shorter than it should be. I think the cable can be ruled out, because I can achieve the 200mm and the 90 degree angle. So the problem is that the adjustment screw can't reach the piston. The screw is standard, as a matter of fact I am even using a different lever at the moment.

    This really rules out all the parts, apart from the piston and possibly the clutch rod itself. There is no wear visible on the clutch rod that might affect the length. The hole in the diaphragm spring is not enlarged.

    It will come down to the piston, clutch rod, or me being a complete idiot. If this thread goes all quiet soon, you'll know which.:lol3

    Again, all input is most appreciated.
    #20