2005 S2R 800 - clutch issues, dragging - PROBLEM SOLVED

[pmazdan9]

Are the plates Barnett?

Nope, OEM.

[ducpainter]

Clutch spring length doesn't affect disengagement, unless the coils bind, and don't allow the pressure plate to travel fully. If you shorten them too much it will slip, but likely not stop the dragging.

Did this problem start to occur suddenly?

Didn't you have another thread about this?

[ducpainter]

I merged your two threads. It will be much easier to follow the progression of what you've done so everyone doesn't have to go through the questions all over again.
If I were to shorten the stack by removing plates, I'd remove that outermost fiber disc.

[pmazdan9]

Clutch spring length doesn't affect disengagement, unless the coils bind, and don't allow the pressure plate to travel fully. If you shorten them too much it will slip, but likely not stop the dragging.

Did this problem start to occur suddenly?

Didn't you have another thread about this?

The problem was there but it got worse after 1500 miles. I suspeced my OEM slave started leaking so replaced it with aftermarket one yesterday (bigger bore) but it didn't make any difference.

Yes I made a separate thread so people don't have to read through the whole thing and I got straight to the point. The issue is not a loose nut, it is something else this time.

[pmazdan9]

I merged your two threads. It will be much easier to follow the progression of what you've done so everyone doesn't have to go through the questions all over again.
If I were to shorten the stack by removing plates, I'd remove that outermost fiber disc.

Do you mean the one that has it's own off set slot in the basket?

/e: I might try to remove 1 friction and 1 steel plate. IIRC my stack height is about 54.5mm and it should be no less than 50mm, so it should still be fine. I'll do it in 2 weeks time as I've got no time now. Good idea or not?
Ignore, it's 52.51mm - can't remove anything as it would be less tahn 50mm. I might get away with removing 1 steel plate but not sure if it's a good idea.

Meanwhile, does anyone have any other suggestions? PO rode with these plates for 10k+ miles so I doubt it will make a difference.

[ducpainter]

The problem was there but it got worse after 1500 miles. I suspeced my OEM slave started leaking so replaced it with aftermarket one yesterday (bigger bore) but it didn't make any difference.

Yes I made a separate thread so people don't have to read through the whole thing and I got straight to the point. The issue is not a loose nut, it is something else this time.

But we'd still ask all the same questions if we didn't read your first thread. This way the info is right there.

Do you mean the one that has it's own off set slot in the basket?

Yes.

I don't see how that plate can stay lined up with that slot.

[pmazdan9]

But we'd still ask all the same questions if we didn't read your first thread. This way the info is right there.

I could have posted a link to this thread instead, just don't want or expect people to read the whole thread only to find out that I've got a separate problem now It's alright though, thanks.

Yes.

I don't see how that plate can stay lined up with that slot.

It does though. Pressure plate does not move far enough for it to jump out if I remember correctly. Unless it's meant to do it in which case I don't have enough pressure, but I doubt it, surely there's a reason for the last plate to be in this position? That's what manual says as well, if it could jump out of place when disengaging the clutch what would be the point of putting it there?

[ducpainter]

I could have posted a link to this thread instead, just don't want or expect people to read the whole thread only to find out that I've got a separate problem now It's alright though, thanks.

It does though. Pressure plate does not move far enough for it to jump out if I remember correctly. Unless it's meant to do it in which case I don't have enough pressure, but I doubt it, surely there's a reason for the last plate to be in this position? That's what manual says as well, if it could jump out of place when disengaging the clutch what would be the point of putting it there?

That's why I changed the title.

In your picture of the stack that plate is out of the slot. Was that picture taken with the clutch completely assembled?

[ducpainter]

This pic... https://ibb.co/MCQLBRZ

[pmazdan9]

That's why I changed the title.

In your picture of the stack that plate is out of the slot. Was that picture taken with the clutch completely assembled?

You're the boss

I think it was taken when the new slave had 10mm spacer in it that I forgot to take out. Ignore it please, it's not relevant.

With the clutch fully assembled properly and torqued it sits in the basket whether the clutch is engaged or disengaged.

[Howie]

Slave with bigger bore means less travel.  I'm not saying this is your problem, just that it will make your problem worse.  What is the stack height of the plates?  Pushrod worn?

[pmazdan9]

Slave with bigger bore means less travel.  I'm not saying this is your problem, just that it will make your problem worse.  What is the stack height of the plates?  Pushrod worn?

That's what I thought as well, maybe it works the same as leaking OEM slave... damn I can't afford another one

Pushrod is perfectly fine. IIRC stack is 52.51mm.

[ducpainter]

I truncated the link by mistake. I fixed it.

Okay, so now we're getting somewhere. Like Speeddog and stopintime that disc with it's own slot makes no sense to me either, but since the manual says so...

If it were me, I'd try different oil first. I understand that moto specific oil is expensive, but we don't know if the issue is stack height, or oil drag. Castrol gets good marks from many for wet clutches.

Once you eliminate the easiest cause, I'd disassemble the stack and measure the steel plates. Ducati often uses both 1.5, and 2, mm steel discs in the stack. If you have access to some used 1.5 mm steel plates you could adjust the stack height to get more disengagement. A half a mm can make all the difference. It's how the engagement is adjusted in a slipper. I'd also verify that all the plates are flat, except for the dished one. A bent disc can cause drag.

I'd probably go back to the stiffer springs if I was playing with stack height to eliminate the possibility of slipping.

That's all I got.

[pmazdan9]

I truncated the link by mistake. I fixed it.

Okay, so now we're getting somewhere. Like Speeddog and stopintime that disc with it's own slot makes no sense to me either, but since the manual says so...

If it were me, I'd try different oil first. I understand that moto specific oil is expensive, but we don't know if the issue is stack height, or oil drag. Castrol gets good marks from many for wet clutches.

Once you eliminate the easiest cause, I'd disassemble the stack and measure the steel plates. Ducati often uses both 1.5, and 2, mm steel discs in the stack. If you have access to some used 1.5 mm steel plates you could adjust the stack height to get more disengagement. A half a mm can make all the difference. It's how the engagement is adjusted in a slipper. I'd also verify that all the plates are flat, except for the dished one. A bent disc can cause drag.

I'd probably go back to the stiffer springs if I was playing with stack height to eliminate the possibility of slipping.

That's all I got.

Thanks, I'll play around with steel plates as I've got 2 clutch packs now. I will try to find thinner ones to reduce the stack height a little. I will also check all of them again for warpage etc as described in manual.

"except for the dished one" - hooold on, is there one steel plate that's different? I didn't notice and can't see anything in manual, are you sure it applies to wet clutches and not dry? In wet clutch, first and last plates are friction.

If it starts slipping I'll go back to longer springs.

If none of these make any difference, I'll try different oil. I doubt it's that though, I've only just changed it and I've always been using it on my other bikes with wet clutches - never had a problem.

Like Speeddog and stopintime that disc with it's own slot makes no sense to me either, but since the manual says so...

This is what manual says:
"Fit the last clutch plate (A) so
that is it "offset" with respect to the
others."

Also the 'new' clutch that I bought had last plate like that. Hmm..

[ducpainter]

Ducati uses a dished plate on the dry clutches to aid in disengagement...works like a spring. It's identified by a punch mark on the teeth.

It may not be included in the wet clutch packs. I don't own any wet clutch Ducs.

If you don't have any thinner discs, you could sand some down on a surface plate using some 180/220 paper.

Don't dismiss the sensitivity to oil of a Ducati wet clutch. It's been a cause too many times with oil that worked fine in other bikes...and I know you say you have all the air out of the system, but you'd be surprised how many times a bleed fixes a clutch that's dragging.