Author Topic: Another Clutch Slipping Thread...  (Read 575 times)

0 Members and 1 Guest are viewing this topic.

Offline PapaFredrico

  • Tricycle
  • Posts: 12
  • AREA: Northwest Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Another Clutch Slipping Thread...
« on: June 08, 2018, 05:05:36 pm »
Hi all.

I've got an 88 C10 that I've recently nursed back to partial health (with the help of the guys in this form - thanks!).

I took it for it's first major ride and encountered a pretty nasty slipping issue that appears to happen when the bike heats up.  Of course this occurred once I got as far away home as possible but the symptoms are as follows:  about 4k and it just slips.  If it's riding fast it's great, smooth shifting and everything else.  I encountered this twice on the way home (usually after being forced to stop and go through towns) and was able to correct it by pulling off to the side and letting the bike cool. 

I sent half a bottle of NAPA Dot 4 through the clutch line with a vacuum pump so I'm confident it's not the fluid and not air in the line.  But I'm not sure where to go here.  From reading these threads it seems the friction zone just is on the very end of the clutch range (which is kinda weird but if that's normal I'll take it).  Is that true?

Bike has almost 55k miles on it.  Just changed the oil before the trip and it's running with Valvoline 10w40 Full Synthetic Motorcycle Oil.  Do I need to change friction plate discs?  Rebuild master cylinder?  What's the order and what works?  I found stuff on Murphskits but then I see other posts where people say just go OEM because everything else sucks.  No idea where to go here.

Thanks for the help! 

Offline Mettler1

  • Iron Butt
  • *****
  • Posts: 3289
  • You want answers? We got answers!!
  • AREA: North Central Area
  • COG#: 1431
  • Membership Level: Active
Re: Another Clutch Slipping Thread...
« Reply #1 on: June 08, 2018, 06:49:46 pm »
   Here is a good possibility. Most of us with C10's have replaced the star springs. Can't say for sure but it's a good place to start.

https://cog.memberize.net/clubportal/clubstatic.cfm?clubID=1328&pubmenuoptID=30889
     
'94 Concours 115,000 miles-- 7th gear,2MM,KB fork brace,Over flowtubes,Stick coils,Tcro shifter,GPS,SiSF'sTorque cams,SPOOKFAK,block off plates, SS brake & clutch lines,KB risers, FENDA EXTENDA, emulators, SiSF carb Spa, Delkevic exhaust, Murphs' knee savers +grips, etc

Offline MAN OF BLUES

  • I Need a Life
  • ******
  • Posts: 8115
  • AREA: North Central Area
  • COG#: 5977
  • Membership Level: Active
Re: Another Clutch Slipping Thread...
« Reply #2 on: June 08, 2018, 07:07:47 pm »
if it's still somewhat operational, and has just began to slip... stop riding immediatly, and replace the single star spring, which is likely broken, you will need to remove it, and find the broken off tabs and remove them also...
and install the newer dual spring, and new nut... the nut is needed, as the dual spring combo is now thicker, so toss the old nut... and don't re use it.
here
https://www.murphskits.com/product_info.php?cPath=1_107&products_id=148&osCsid=oab62HZno7Bj-8hRScU1

most times this is all it needs, if you stop riding right away, no need to replace friction plates... if you keep riding, you will end up replacing those at $80+ for a set... if you do end up needing them, use the OEM, not aftermarket, friction plates, which are a soak and drop in replacement, due to thier thickness, the won't require messing with various thickness steel plates, to get the correct stack height.

30 YEARS OF KAW.....Rich R. (the other one..)  COG 5977  JUSTAMEMBAHNOW
and if you are gonna call me names... it's MR. Analdweeb if you please...

Offline Bob_C_CT

  • Sport Tourer
  • *****
  • Posts: 2063
  • AREA: Northeast Area
  • COG#: 9544
  • Membership Level: Active
Re: Another Clutch Slipping Thread...
« Reply #3 on: June 09, 2018, 11:51:24 am »
I wonder if your clutch slave cylinder is gunked up and you are always on the verge of the friction zone and as the bike/fluid heats up it gets worse. The clutch slave is known to get gunked up and not allow full function.
97 C10,ZRX Front, Meanstreak rim

Offline turbojoe78_MA

  • Street Cruiser
  • ****
  • Posts: 883
  • AREA: Northeast Area
  • COG#: 8645
  • Membership Level: Active
Re: Another Clutch Slipping Thread...
« Reply #4 on: June 09, 2018, 11:59:24 am »
Another thing to check is your fluid return hole (the smaller one) in the master cylinder.

I know you said that you changed out the fluid, but you would still be able to vacuum all the fluid through with the return port clogged.

What can happen is when you start the bike the fluid is cold and under no pressure so the clutch works right.  As the bike heats up, the fluid heats up and expands, flowing back to the master through the return port.  If the return port is clogged, when the fluid heats up and expands, it has no where to go so it puts pressure on the clutch slave causing the clutch to slip.  This can happen with brakes too, but with brakes, as the fluid heats up it causes the brakes to start applying on their own.  This happened on my 86 Ninja after not having been ridden for a couple years.

I removed the master cyl. and cleaned it out good, flushed the fluid and all was good.  You might want to vacuum all the fluid out of the clutch master and take a strand of thin wire and poke around some in the small return port to see if you can un-clog it, if that's the problem.
1968 Honda 160 Scrambler,  Sold / 1979 Kawasaki SR 650, Traded in for next one,  1978 Kawasaki KZ 1000 Z1R Turbo Sold / 1986 Kawasaki ZX 1000R Ninja / 1999 Kawasaki Concours / 2014 Kawasaki Concours 1400  COG memb# 8645


Offline connie_rider

  • "OtP" {retired/assistant} Slave Labor
  • I Need a Life
  • ******
  • Posts: 8515
  • Help us make "OtP" possible! "AGAIN"
  • AREA: South Central Area
  • COG#: 4154
  • Membership Level: Asst. Area Director
Re: Another Clutch Slipping Thread...
« Reply #5 on: June 09, 2018, 12:51:45 pm »
As Bob sed; The slave cylinder is known to corrode internally.
                   The corrosion can stop complete movement of the slave cylinder.
                   EZ to open it up and remove the corrosion.
                      Probably the first thing you should try as it's free.

As MOB sed; The early C-10's had a Star Spring that broke easily.
                   Can normally be felt as a strange clutch engagement.
                   Replace with the later model star spring.
                    Most probable, but costs a few $$.
                    MOB will have details, but I recall that you need to buy both spring and nut.

As Turbo sed; The return hole sometimes stops up.
                     It is a possibility too, while doing your slave cylinder, can be cleaned.
                     I suspect the other 2 will fix your problem.

Lastly: {I think I recall} I added an extra {thin} steel plate to my 86.
                (At that time I was too poor to buy a set of clutch plates).
                 MOB may ding me on that, but it worked.. :nananana:

Ride safe, Ted               

                   
                 
14 Connie (Traveler II) / 03 Connie (Buddy)
Gone but not forgotten; 87 and 00 Connies..

If your not already a COGger, "consider becoming one".
Help us make "OtP" possible again!!

Offline SteveJ.

  • I Need a Life
  • ******
  • Posts: 5636
  • AREA: Southeast Area
  • COG#: 5603
  • Membership Level: Active
Re: Another Clutch Slipping Thread...
« Reply #6 on: June 10, 2018, 02:32:00 pm »
My 99 developed a slipping clutch. It turned out to be the springs in the clutch pack were under length, probably an issue. New springs fixed it. At 200k miles the fibers still had about 30 percent left.

On TDY at Douglas City CA.
Yeah, if you want true ram air tuning, you better be willing to ram some air! (SiSF)
Tick Tock, baby (Ironbuttal)
Steve J  Tavares, FL, one of the Floriduh Steves
'15 Versys650LT, '98 KLR650, (back home), '99 C-10, 234k miles sold

Offline PapaFredrico

  • Tricycle
  • Posts: 12
  • AREA: Northwest Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Re: Another Clutch Slipping Thread...
« Reply #7 on: June 14, 2018, 11:56:01 pm »
Thanks everyone for the advice.

I ordered a rebuild kit for the slave and master cylinders.  Both arrived in the last two days.  I also ordered the kit from Murphs with the gasket and the two springs.  It showed up today.

I'm looking to run through them all this weekend...  Maybe...

Offline MAN OF BLUES

  • I Need a Life
  • ******
  • Posts: 8115
  • AREA: North Central Area
  • COG#: 5977
  • Membership Level: Active
Re: Another Clutch Slipping Thread...
« Reply #8 on: June 15, 2018, 12:29:47 am »
well, with your 'maybe' statement, I suggest using the FSM if you have one, and doing the star springs inspection/replacement ( IF BROKEN) before jumping into rebuilding the slave and master cylinders... only because it's much easier to see, as if there is a FINGER OR TAB, or 2 missing, it's visible upon dis-assembly... and once reassembled, and working, you can go on to doing the hydraulic rebuilds. Doing them first, is kind of a waste of time, as if the star spring is broken, which is VERY likely, you wasted hours of time and fluids, to end up doing something that was free to inspect prior.(remove cover, 6 bolts on pressure plate, and inspect.)
Best of luck

30 YEARS OF KAW.....Rich R. (the other one..)  COG 5977  JUSTAMEMBAHNOW
and if you are gonna call me names... it's MR. Analdweeb if you please...

Offline Hardhead

  • Tricycle
  • Posts: 17
  • AREA: South Central Area
  • COG#: Forum
  • Membership Level: Forum Subscriber
Re: Another Clutch Slipping Thread...
« Reply #9 on: June 22, 2018, 12:39:09 pm »
Hi all.

I've got an 88 C10 that I've recently nursed back to partial health (with the help of the guys in this form - thanks!).

I took it for it's first major ride and encountered a pretty nasty slipping issue that appears to happen when the bike heats up.  Of course this occurred once I got as far away home as possible but the symptoms are as follows:  about 4k and it just slips.  If it's riding fast it's great, smooth shifting and everything else.  I encountered this twice on the way home (usually after being forced to stop and go through towns) and was able to correct it by pulling off to the side and letting the bike cool. 

I sent half a bottle of NAPA Dot 4 through the clutch line with a vacuum pump so I'm confident it's not the fluid and not air in the line.  But I'm not sure where to go here.  From reading these threads it seems the friction zone just is on the very end of the clutch range (which is kinda weird but if that's normal I'll take it).  Is that true?

Bike has almost 55k miles on it.  Just changed the oil before the trip and it's running with Valvoline 10w40 Full Synthetic Motorcycle Oil.  Do I need to change friction plate discs?  Rebuild master cylinder?  What's the order and what works?  I found stuff on Murphskits but then I see other posts where people say just go OEM because everything else sucks.  No idea where to go here.

Thanks for the help!


 You have to use the right oil in this bike http://www.whitedogbikes.com/whitedogblog/choosing-the-right-motorbike-oil-what-does-jaso-and-jaso-ma2-mean/  If you did not, change the oil first. If you glazed the plates you can glass blast the friction plates and measure the stack height to see if they meet spic. if not you can buy spacer plates of different thickness to get the stack high back to spec.. There is no need to replace all the clutch plates. You also need to change out the star spring along with the NEW NUT. This should solve your problem. DO NUT USE OIL IN THE CONNIE THAT DOES NOT MEET THE JASO SPEC.

« Last Edit: June 22, 2018, 12:43:28 pm by Hardhead »