Clutch cable only!? - Keeping fingers crossed

[kiwiz]

70Km into my "run in" of the wiseco powering up a hill with the missus on behind and there is a sudden slackening of the clutch cable and suddenly no power being transmitted to the rear wheel, as though the machine is in neutral.

Fortunately I was only a Km from home and mostly downhill so it was a push /coast there (I new she was on the back for a reason).

Parked in the garage I am musing over the transmission and wondering if I should rip into it now or have a quiet sunday afternoon in contemplation.

Facts. The clutch cable is now incredible slack as though a nipple has pulled off but that's a brit bike phenomena. The engine runs just fine as though its in neutral. Spinning the rear wheel seems to allow me to select all the gears but there is absolutely no resistance from the engine. Noticed a slight clutch slip on a change on an earlier ride but I put that down to dirty plates since the bike had been standing over 9 months.

The clutch action has always been quite heavy on this machine and I am wondering is some how the clutch operating mechanism has jammed lifted. I had a look at this mechanism some time ago when the lever action became almost impossible for my weak wrists to operate and noticed it was filled up with a lot of oily crud which I cleaned out.

Any ideas on what could be the problem ?

[Jeff Saunders]

Were you pulling the clutch in for a gear change when the problem occured?

Normally a broken cable will leave you in gear - and the rear wheel being driven.

I would suspect either a broken clutch plate, or the worm gear in the sprocket cover has jammed.

The simplist thing to check is the worm gear. If it's not that, then it's time to pull the clutch cover off and investigate the clutch pack.

[Pigford]

Sounds like the worm gear is stuck in, so clutch is disengaed! Hopefully thats all it is, so whip that cover off and free it up, and you'll be up and running again! Its usually the simplest of things!
Don't forget to carry the pillion again tho! :laugh:

[Rich]

Sounds like the worm gear is stuck in, so clutch is disengaed! Hopefully thats all it is, so whip that cover off and free it up, and you'll be up and running again! Its usually the simplest of things!
Don't forget to carry the pillion again tho! :laugh:

I'd second that - did you tighten the lock net when you adjusted it?

[kiwiz]

Guys,


Thanks very much for your suggestions and the verdict seems to be in favour of the worm gear which has given trouble before.

Clutch action had been very stiff on prior occasions and yes it is always possible with me that I may have left the adjusting lock nut loose when I took out the worm to clean out the housing, the crud in which seemed to contribute to the stiffness. That really raises another question about why the crud is there. There seems to be continued oil seapage out of the gearbox, and I have not been able to figure out where the oil is coming from. This has been a feature of the bike in the decade I have owned it. I have previously replaced the three seals in the gearbox drive side and the drive sprocket but the seapage continues; enough to leave a a coin sized puddle after a run. Frankly I am mystifed how the oil is seeping out and if a seal, which one. The drive shaft seal seems the likely culprit but I have replaced both items.

Jeff to answer your question; I had declutched to change up from second to third when suddenly the lever went slack. Engine runs freely like in neutral or declutched, and I seem to be able to engage all gears. The bike just coasted to a stop after the "incident". So hopefully thats the answer.

[debben1]

Hello Kiwiz, it could be the clutch lifter (the steel mushroom behind the pressure plate), has the bike been uprated with the KCB900 roller bearing clutch lifter yet? The stock steel item is prone to spining around against the pressure plate and then friction welding itself to the ball bearing thats located between the pushrod and the lifter, these 3 parts then become one, the result is an extra couple mm of free play. You should check this rather than adjust out the free play, I have seen the result of ignoring this and the clutch push rod, bearing and pusher assembly then friction welding itself to the input shaft. Remove the clutch cover, pressure plate and lift out the pusher, while your there it would pay to check the plates as suggested by Jeff, and the clutch hub nut. Regards, Steve

[kiwiz]

Steve,
will have a look at that once I have eliminated the worm which has given trouble before. I very much doubt that the lifter has been modified as I have owned the bike since 1996 and I certainly haven't done so.

Thanks for your advice.

Couldn't resist the temptation after work to pull off the engine spocket cover and examine the worm.

This is a late model release which uses a rolling ball ramp mechanism. My observation that the clutch release arm is at rest at a 1 o'clock postion if you look at the inside of the cover. To declutch the cable pulls the lever anti clockwise to about 11 o'clock which is the shortest free cable length between the release arm and the cable/cover entry hole. At this point the lever seems to have rolled right out of the ball groove and there doesn't seem much incentive for it to return to the 1 o'clock rest position other than the efforts of a light spring on the end of the clutch cable. My feeling is that the the lever rotated right out of the ball groove and clutch spring pressure held it there, leaving the clutch declutched (if that makes any sense!). This makes me wonder whether I assembled the release mechanism correctly the last time I looked at it. The lower ramp mechanism has a tab on it which seems to locate it with no chance of error, but the 3 balls and their circular cage seem to have a section cut off one side and is capable of being put in 3 postions. I have no idea the significance of this cut out, assuming it was for lubrication purposes. Mine was set with the cut off at 3 o' clock. My Clymer manual doesn't seem to show the set up. Does this set up sound correct? If it is correct maybe I need a bigger spring but that would just seem to make that action even heavier.

Also does anyone have any suggestions on how to trace which seal is leaking? Someone suggested cleaning the area throughly and wiping the areas around the seals with talc powder, the oil leak then leaving a trace in the talc???

[Rich]

The spring pressure of the clutch should make it return, the cable spring is only to keep the nipple in the arm.
Leaking seal : clean : talc : ride and take cover off to inspect. It may be from the back of the engine and finding its' way down. Do you have a chain oiler?

[kiwiz]

Rich,

thanks for your comments.

I am sure that at the point of minimum free length in the cable (in the 11 o'clock position) the balls are right out of the ramped groove. I have tried it on the bench with my hand where in this position no amount of side thrust as would be applied by the pushrod on the cover lever will generate any form of rotation. If the balls are still in the groove the side thrust does cause the lever to rotate back to the correct 1 o'clock rest position. It just seems that applying a full pull on the handlebar lever allows the cover lever to rotate too far. This may be because my adjustment is off with too much clearance.

On the seals:No chain oiler fitted. Will give it a good clean talc it and see if we can see the offending area.

[Rich]

When you took it to bits did you put it together the right way, I will have a look at the book and dig through my boxes to check mine, but it may be at the weekend as I have to finish spraying at the moment.

[kiwiz]

Rich,

I have no idea if it was assembled correctly before as the last time I looked at it was about a year ago. But worked okay up till now. Hence my attempt to descibe how I have set it up now: lever at rest 1 o'clock, ball cage cut out at 3 o'clock.

As I mentioned I mave have too much rod clearance but another possibility is some flex in the cover itself as 1 of the 4
cover fasterner holes is stripped and this is the lower left close to the push rod. I have been holding the cover on with 3 bolts for the last decade!

Anyway its easy to put the lever in what it think is the correct position put the cover back on adjust the rod clearance and see if it works. If that fails I will look at the other side of the clutch as Steve suggested.

[kiwiz]

Dismantled the clutch operating lever and reassembled. Put the cover back on and Wow! the clutch worked again.

As I suspected the operating lever had over rotated and moved out on the inclined grooves, locking into the declutched position.

Why is the real question. It may be that before it had been assembled incorrectly. There is little discussion about this set up in the Clymer. It seems that the cut out in the bearing cage may be to accomodate a peg which holds one of the "cams" in place. It may also be that there was too much adjustment clearance, allowing over rotation. Whatever it was we are mobile again.

Has anyone else had an experience like this?

[phil churchett]

Just about all the clutch problems that i have had with my Zed in over 20 years, has been down to the worm gear [and it is still on the original clutch, nearly 70,000 miles].
I think it is a combination of muck and wear in the clutch cable that causes the problems.

[kiwiz]

After another exactly similar incident as the first which required the wife to ferry out the tool box to me at 6AM Sunday morning so I could free the clutch, I decided to have another look at the declutch system.

I had previously followed the clutch adjustment as specified in the Clymer manual to the letter. This I believe was the mistake. The manual says the clutch adjuster is to be turned clockwise until it meets resistance and then is backed off quarter of a turn. This is precisely the method that I have used on all other (Brit) bikes to adjust the clutch rod clearance. However on examining the J declutch mechanisn I am convinced that the system works the other way around; that is to reduce the clearance the adjuster is screwed counter clockwise until it touches the rod and then is backed off a quarter of a turn in a clockwise direction. This has restored the declutch function whereas the way I had been setting it gave excess clearance allowing the lifter cam to over rotate and jam.

This suggests that the Clymer J manual is 100% wrong with regard to its instructions on adjusting the clutch clearance.

Can anyone with a J confirm that the rod's clearance is reduced by turning the adjuster counter clockwise?

[Rich]

I would screw the adjuster screw in (clockwise unless it is a left hand thread which I don't think it is) and then back it out 1/4 turn, holding it steady while tightening the locknut up.
If it is locking up when hot is the pushrod the correct size for the shaft, 1015cc lumps have a 7mm dia rod, GPZ11s have a 8mm dia rod. what size does the j have?
Do you have the bearing pressure plate? Is the bearing alright? does it lock up when hot ? Have you left some slack in the cable - there should be 2-3mm free play at lever or you will be riding the clutch all the time.


Official Kawa Manual "screw adjuster screw in clockwise until it becomes hard to turn then back out 1/4 turn counterclockwise and tighten locknut"