Clutch slipping - really?

[bluebossa]

Ah and on we go into the next adventure into Mechanical K wonder land...
Took Bike out today for a sunshine run with a buddy of mine on a Guzzi - 150 miles of loveliness.
Now that I'm on full power I could feel some slip, watched the revs rise, in Third and Fourth on full throttle... not all the time, but most of the time.

I adjusted the clutch to the Book the other day, once the Bike had settled - 75mm of clutch cable, back off the locknut, adjust in till a minor bite then lock up, finally tweaking the cable at the handlebar to give freeplay 2.5mm, so all is well there.. or at least as per the book.

Question or two -
1. How long do K Clutches generally last? - mine both have circa 50k miles on them and looked good.
2. The Clutch actuator touches the exhaust joint when fully out - you can hear it knock when stationary i.e. it butts to the Muffler/Silencer - is that by design or is it perhaps stopping the actuator from coming back? If so maybe a Grinder is called for to clear the way...
3. Any tweaks I can make on adjustment to prove it out either way?

Just wanted some advice from the Oracle before resigning myself to a Gearbox off job again - might run it some more until weather goes but then bite the bullet.
Bike is still settling in post Engine change so also wondering if it might be just a bit of Oil that might burn off in time? Everything was dry on assembly.

Thanks in advance...

[Laitch]

Question or two -
1. How long do K Clutches generally last? - mine both have circa 50k miles on them and looked good.
2. The Clutch actuator touches the exhaust joint when fully out - you can hear it knock when stationary i.e. it butts to the Muffler/Silencer - is that by design or it stopping the actuator from coming back?

When the opportunity comes to measure a clutch disc rather than just look at its goodness, it should be taken but that requires investing it a measuring tool, like a micrometer or vernier caliper. How did you measure the 75mm clear cable length?

The clutch arm bolt shouldn't bite the clutch bearing; it should just touch it. My clutch system is adjusted so the clutch arm doesn't knock the muffler. Also, be certain the free play is actually free. I can move the lever lightly through the free play distance with one finger.

Clutch discs last longer when the operator knows how to engage them. Who knows how it was handled before you got it? Wearing out at 50K seems premature to me. Is any engine oil around the weep hole? Regardless, stripping the rig down for clutch replacement should be a minor matter for somebody with your experience. Alternatively, somebody who has the right touch probably could travel 10K miles or more with a clutch like that, hardly have it slip at all and continue to enjoy the ride.

[bluebossa]

When the opportunity comes to measure a clutch disc rather than just look at its goodness, it should be taken but that requires investing it a measuring tool, like a micrometer or vernier caliper. How did you measure the 75mm clear cable length?

The clutch arm bolt shouldn't bite the clutch bearing; it should just touch it. My clutch system is adjusted so the clutch arm doesn't knock the muffler. Also, be certain the free play is actually free. I can move the lever lightly through the free play distance with one finger.

Clutch discs last longer when the operator knows how to engage them. Who knows how it was handled before you got it? Wearing out at 50K seems premature to me. Is any engine oil around the weep hole? Regardless, stripping the rig down for clutch replacement should be a minor matter for somebody with your experience. Alternatively, somebody who has the right touch probably could travel 10K miles or more with a clutch like that, hardly have it slip at all and continue to enjoy the ride.

75mm measured with a Tape measure - not an exact science but close.
Bite - OK so maybe back it off a little, until it's totally free, not sure why Arm clunks on muffler... puzzler
Free play is one finger free - but will double check
50k - that's what I thought, I've read on here that they last for double that - no Engine Oil of note.. will again double check

I'm OK with doing it - just wanted to try and avoid it if it wasn't gone.... cheers

[Laitch]

75mm measured with a Tape measure - not an exact science but close.

Maybe if it were exact, the arm wouldn't clunk. Nevertheless, it's not mysterious; it just involves compensating adjustments done in the correct order.

[Martin]

I replaced mine at a 140,000 K's and it had only worn .5mm hardly worn. I only replaced it because it was a special order and couldn't be returned.
However riders vary some are easy on clutches and some are hard.

Regards  Martin.

[Filmcamera]

Chris Harris has a very good video on adjusting the clutch - I used it when I installed a new clutch cable recently and it has worked great so far

[johnny]

greetings...

number 1 reason for clutch slipp is improperly adjusted clutch...

number 2 reason for clutch slipp is oil getts in there...

number 3 reason for clutch slipp is its worn out... generally abouts 80 to 100 thou hard 2 up miles... 120 to 150 thou hard 1 up miles...

i have done 4 clutches... all were oiled... gotta chase that adjustment throughout its life though... when you see poo out the hoe you are gonna have to do it sooner or later...

i have gone 10s of thousands of miles on a leaky slipper and i have ridden a hundert miles in 1st back to the barn cause i gotts nothing 2nd thru 5th with no warning...

j o

[bluebossa]

I replaced mine at a 140,000 K's and it had only worn .5mm hardly worn. I only replaced it because it was a special order and couldn't be returned.
However riders vary some are easy on clutches and some are hard.

Regards  Martin.

Thanks Martin - so that's 100k Miles ish… double mine...

[bluebossa]

Chris Harris has a very good video on adjusting the clutch - I used it when I installed a new clutch cable recently and it has worked great so far

Excellent - I watched his repairing Grips one last night - will watch this now Ta..

[bluebossa]

greetings...

number 1 reason for clutch slipp is improperly adjusted clutch...

number 2 reason for clutch slipp is oil getts in there...

number 3 reason for clutch slipp is its worn out... generally abouts 80 to 100 thou hard 2 up miles... 120 to 150 thou hard 1 up miles...

i have done 4 clutches... all were oiled... gotta chase that adjustment throughout its life though... when you see poo out the hoe you are gonna have to do it sooner or later...

i have gone 10s of thousands of miles on a leaky slipper and i have ridden a hundert miles in 1st back to the barn cause i gotts nothing 2nd thru 5th with no warning...

j o

Thanks Johnny - Just been under it and given it another tweak, backed off the locknut and let it out a bit, made sure it didn't Bite on the way in, locked it up
- guess it might have had 1mm of bite - I read "Haynes" that you had to have it lightly bite, but obviously not from what Laitch has said...

Took it for a test ride and thrashed it a bit to see if I could make it slip and it seemed good - no discernable slip, here's hoping... it held under full power in all gears.

No Oil from Weap hole under Engine or leaks - all seems well.

100 to 150k Miles then - way more than mine, though like others have said who knows how it was treated for 50k
- it's a new to me Clutch with the Engine I fitted and I left it in situ, didn't measure it as I figured it was dry and should be good - my other had also done similar mileage so left it alone.

Time to ignore and ride some more... !
Cheers

[Laitch]

. . .  i have ridden a hundert miles in 1st back to the barn cause i gotts nothing 2nd thru 5th with no warning...

That's an excellent way to take in the countryside and check off birds on your life list.

[bluebossa]

On further tweaking, it doesn't feel like the side stand release actuator is operating as at might...

Should the side stand lever be pushing back the Clutch actuator - by way of it's spring?
i.e. the Side stand actuator ensures that the clutch actuator is fully out.... places pressure on it

It feels tight and not freely moving - even on full adjustment it doesn't seem to release the stand through the clutch lever.

I've watched the Chris Harris video a couple of times but mine won't just adjust like that - still clonking on Exhaust, though I'm now more sure of releasing..

[Laitch]

On further tweaking, it doesn't feel like the side stand release actuator is operating as at might...
Should the side stand lever be pushing back the Clutch actuator - by way of it's spring?

I can't understanding your second sentence. When the cable rotates the side stand cam past a certain point, the force of the spring tension finishes the retraction.

Grease the side stand.

The clutch cable is designed to operate both the clutch arm and the side stand release mechanism. This arrangement is intended as a safety feature to prevent riding off with the side stand down causing damage and injury at the next left turn or during an ebullient weaving down the road commemorating the power and freedom of motorcycling.

This system had to be designed to retract the side stand so that the cable and lever wouldn't be damaged by forgetful he-people riders attempting to dominate friction and inertia by using their grip strength and iron wills. The drawback of this system is that its misadjustment coupled with regular use of the clutch lever to retract a stand that is almost in a state of seizure from corrosion and grit can weaken—maybe even stretch—the cable, making clutch adjustment more problematic.

I recommend using the retracting feature only as a reminder. When you feel the slightest resistance in the lever, kick the side stand into position instead of stressing the clutch cable. Otherwise, adjust the system so the force of a grandmother's cheek pinch can retract the stand.

Lubrication of the side stand might help but you might need a new cable to bring things back to spec.

[bluebossa]

I can't understanding your second sentence. When the cable rotates the side stand cam past a certain point, the force of the spring tension finishes the retraction.

Grease the side stand.

Hi Laitch - what I'm trying to ask is..... Is the design such that the Side Stand Actuation lever pushes onto the Main Clutch Actuation lever in the drive/engaged position?

I can see that the Side stand lever is stiff and sitting in the mid position - the spring is not effective - is it this action that ensures that the clutch actuation lever is fully out when in drive, thus not placing any pressure or actuation onto the Clutch mech - if so mine isn't performing that, hence the clutch actuation lever is coming back of its own accord... which might cause a slip if it's not fully out...

I can take a photo if that doesn't describe my ask well enough...

Or does A push onto B via the Spring action when not being asked to retract side stand - diagram attached - to ensure clutch is fully engaged, i.e the force of the spring keeps it out....

[Laitch]

what I'm trying to ask is.....

What I suggest is that you put the moto up on its center stand, get a yoga mat, sleeping bag, rug remnant, tarp or empty, collapsed refrigerator carton, place whichever you select from that list on the floor next to the side stand, put on a headlamp, set the headlamp to its brightest output, lie down on the floor covering, then move the side stand from its extended to its retracted position repeatedly while you analyze the operation of its mechanism.

Take as long as you like. On breaks, review the Harris video. Stay hydrated.

[bluebossa]

What I suggest is that you put the moto up on its center stand, get a yoga mat, sleeping bag, rug remnant, tarp or empty, collapsed refrigerator carton, place whichever you select from that list on the floor next to the side stand, put on a headlamp, set the headlamp to its brightest output, lie down on the floor covering, then move the side stand from its extended to its retracted position repeatedly while you analyze the operation of its mechanism.

Take as long as you like. On breaks, review the Harris video. Stay hydrated.

hmmm - I'd like to say thanks, but your response doesn't merit it... we have a saying here... your response was about as useful as a Chocolate teapot.

[Laitch]

hmmm - I'd like to say thanks, but your response doesn't merit it... we have a saying here... your response was about as useful as a Chocolate teapot.

Good luck.

[rbm]

Hi Laitch - what I'm trying to ask is..... Is the design such that the Side Stand Actuation lever pushes onto the Main Clutch Actuation lever in the drive/engaged position?

I can see that the Side stand lever is stiff and sitting in the mid position - the spring is not effective - is it this action that ensures that the clutch actuation lever is fully out when in drive, thus not placing any pressure or actuation onto the Clutch mech - if so mine isn't performing that, hence the clutch actuation lever is coming back of its own accord... which might cause a slip if it's not fully out...

I can take a photo if that doesn't describe my ask well enough...

Or does A push onto B via the Spring action when not being asked to retract side stand - diagram attached - to ensure clutch is fully engaged, i.e the force of the spring keeps it out....

The coil spring in your diagram imparts a counter-clockwise rotational force against the side stand return lever "A" such that there is always tension applied to the actuator rod.  With the side stand retracted, the actuator cam at the side stand pivot is relaxed, the spring is applying counter-rotational force to the return lever "A" and there is maximum distance between "A" and the clutch actuator arm "B".  In this arrangement, the clutch actuator arm "B" is offered the greatest room to pivot without ever encountering the return lever "A". 

When the side stand is deployed, the actuator cam is engaged, causing it to pull on the actuator rod which in turn applies a clockwise pivoting motion to the return lever "A".  "A" pivots to the point it touches or nearly touches "B".  In this arrangement, the clutch lever arm "B" is hindered from moving because the return lever "A" is touching it.  Thus, if the motorcycle pilot attempts to select a gear while the side stand is deployed, they must first pull the clutch. The actuator lever arm "B" cannot freely move and the pilot will feel great resistance at the handlebars.  If the pilot continues to pull on the clutch, the actuator lever arm "B" will push on the return lever "A" which will  pull on the actuator rod and cause the actuator cam to flip up the side stand.

The objective is to adjust the nut on the actuator rod such that the return lever "A" offers sufficient room for the clutch actuator lever "B" to operate unhindered with the side stand up, but touches or nearly touches the actuator arm with the side stand deployed.

Whew, I hope this makes sense!

[The Mighty Gryphon]

The clutch arm on my K75RT also hits the muffler and rattled when the engine was running.  I stopped the rattle by shortening the cable length from 75mm to just enough that it didn't clank when the clutch lever is allowed to snap out.  Then go back and do the rest of the clutch adjustment as the instructions direct.

My clutch has been adjusted this way now for over four years and nearly 40,000 miles with no problems.