Author Topic: frozen / very sticky clutch  (Read 2549 times)

Offline phillyfyk

  • Curious
  • Posts: 3
frozen / very sticky clutch
« on: November 12, 2018, 09:34:01 PM »
hi all,
I'm new to the forum and the k bikes so if this is not well searched enough or in the wrong place, feel free to let me know.
recently bought an 85 k100 to commute from Philly to NYC, as my f650 wasn't cutting it on the jersey turnpike. I've found that when i run it on the highway for 20 minutes or more in a 5th gear, when i go to pull the clutch lever to downshift its REALLY HARD, like it feels frozen. I've found that i can pump it, and as i squeeze it over and over it loosens up a bit with every pull. it takes 12-15 pumps to get all the action back. doesn't seem to be a problem in town. my searches on here have indicated that i might need the clutch splines lubed? i cant seem to find anyone posting with the same symptoms as me. any insights would be great
  • Philadelphia, PA
  • 85 K100, 99 F650

Offline The Mighty Gryphon

  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 6617
Re: frozen / very sticky clutch
« Reply #1 on: November 12, 2018, 10:05:06 PM »
It does sound like something is experiencing stiction.  Starting at the top,it could be the cable.  How old is it?  If you disconnect both ends, how hard is it to move?

Then there is the arm at the bottom end of the cable that transfers the cable motion to the clutch push rod that runs through the transmission.  The arm has bearings that get loaded up with dirt and become very hard to move.  It's in a spot where a lot of road dirt and water get thrown on it, yet it is almost impossible to clean.  This is where I suspect your problem is.  There is info here on cleaning it.  Some of us have drilled it out and installed a grease fitting to help keep it lubricated. 

The pushrod may be bent, but that would make it hard to activate all the time, so I doubt that is your problem.

Last is the clutch splines.  These need to be lubed, but make it difficult to fully release the clutch, making downshifts very difficult.  I am not that sure that lubing them will reduce the resistance in the lever pull.

Bottom line, go after the clutch arm behind the transmission.
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline phillyfyk

  • Curious
  • Posts: 3
Re: frozen / very sticky clutch
« Reply #2 on: November 12, 2018, 10:42:13 PM »
thanks gryphon.
i started by lubing up the clutch cable. disconnected it to do that and it slid freely. saw the big clutch arm while i was down there. seemed ok when i was pulling on it but ill dig into it a bit more.
  • Philadelphia, PA
  • 85 K100, 99 F650

Offline Martin

  • ^ Quintessential Motobricker
  • Posts: 4437
Re: frozen / very sticky clutch
« Reply #3 on: November 12, 2018, 11:46:41 PM »
If you are going to lube the clutch cable use a PTFE based lubricant some other types of lubricants can degrade the Teflon liner. Lube the cable every second service.The addition of a grease nipple to the clutch arm is really a must do if you wish to avoid water and dirt ingress into the pivot shaft. It is easy to squeeze a couple of shots of grease into the nipple every couple of services. By doing both you will extend the life of your cable.
you also need to lubricate the nipples at either ends of the cable and lubricate the lever pivot and contact points.
Regards Martin.

* Clutch grease nipple 2.jpg (38.33 kB . 768x576 - viewed 233 times)
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline phillyfyk

  • Curious
  • Posts: 3
Re: frozen / very sticky clutch
« Reply #4 on: November 13, 2018, 08:49:42 PM »
will do.
thanks for the pic. its worth a thousand words.
  • Philadelphia, PA
  • 85 K100, 99 F650

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