Ducati Monster Forum

for more info see
https://www.ducatimonster.org/forums/tech/355352-s2r-clutch-not-fully-disengaging-engine-2.html

Join Date: Jul 2017
Posts: 6

S2R - Clutch not fully disengaging engine
I have a 2006 S2R 800 and the clutch lever doesn't seem to completely disengage the engine when trying to roll the bike around in 1st gear. Finding neutral is easy enough, and it shifts nicely, although it goes into 1st gear with a smidgen of a clunk.

I cleaned up the clutch slave, flushed the fluid and changed the oil, but it's mostly the same.

The bigger issue is that when I start it in gear, the bike will move forward a bit. I can hold it back with my legs, and once I run it a bit, the issue lessens. But I wonder how I would know if the slave cylinder is moving enough? Or is it something else?

and more folks noting same on a facebook site for s2r only
so we are the folks that bought your used s2r800 and well, what did you not tell us?  [laugh]

Slave cylinders can weep enough to only evaporate the leaking fluid via engine heat. Master cylinders can leak. Bleed nipples can crack from over torquing. All introduce air and lose fluid, so not all leaks are obvious.
Too heavy an oil can cause clutch drag as much as auto oil can cause slip.
Completely purging the system of air can be more difficult than one thinks as tiny air bubbles can get lodged in nooks and crannies. Bleeding methods for brakes and clutches have been widely discussed and worth a search here for some innovative methods including bleed tools, vacuum method, syringe methods, sonically releasing bubbles and cable tying the lever overnight. Ime these issues can occur with any motorbike.
That said the slave cylinders have been a known issue for Ducati.

My S2R has clunked into first since new, and it has 36k miles on the clock now. It what multiplayers clutches do.

Put the bike in neutral when you push it around and the problem is gone. ???

Seems like it does everything else correctly.

If you can find neutral easily at a stop, with the engine running, that's as good as it's going to get.

Honestly, you shouldn't be starting it in gear, that's not safe and you're just making life more difficult for the starter.

it has been suggested it is unique to certain monsters
because of http://www.adige.eu/public/ENG/products/aptc.asp
with its wet APTC 'slipper clutch'
any thoughts

Nope.

Two things, though.

If you're not using a motorcycle-specific oil, that's a problem.
What oil are you using?

And if your clutch has Barnett aftermarket plates, that's a problem.
Unlikely, as you can find neutral, if you have Barnett plates and the engine's running you can't.

no to the barnetts
and yes to motorcycle oil
although i have experienced this in the past
i am really just derbying anothers post because i am curious as to why it happened to me

really oil. hmmm
do you think it could be  synthetic oil vs non-synthetic oil
it is weight

In my 750 I used a fully synthetic moto oil of a very good local brand and it clunked badly into first and dragged in use. That same oil works beautifully in dry clutch 900's, 1000's and 1100's. Changed to another full synth brand and it was much better. Both good brands, but its been reported that the wet clutches are oil sensitive to brand additives and grade.

Note this blokes comments carefully..

Sounds like your bike is just fine.  Wet clutches do drag do to the oil, particularly when cold.  It wouldn't hurt to remove the slave and inspect, then bleed the system for peace of mind.

That's the thing about full synthetics...they don't contain much in the way of additives. That's why they can do their job for so long without breakdown.

I wonder how the new gen of Duc wet clutches perform?

All this is just wondering. It seems like there's really no problem with convict's bike.

The only new clutch that had issues to my knowledge was in the Hyper 821, but they updated the pack which fixed it.

The well regarded local Penrite brand oil has a lot of zinc in it among other things. It doesnt suffer from the big bore blow-by that Motul full synth can, but it is a bit heavy for some wet clutches. Some classic big bore racers were avoiding Motul due to bad oil loss and using Penrite instead, but they probably have dry clutches. My 750's clutch hates it but likes the Motul, Castrol or Shell full synth 10-40.

Are all these 10w base stocks?

I dont know the tech data on those oils, but they flow and splash easily when decanted. Penrite 10/40 is visibly more viscous at room temp and how it comes out of the bottle, it reminds me of old straight 50. The V8's and big bore single and twin motorcycle engines love it.

They make a point about the zinc additive, I wish I could ask George about it. RIP. :-\

Sounds like Penrite is doing something unconventional. 10w full synthetic should pour like 10w.

No wonder a wet clutch doesn't like it.

It's quite obvious to the eye for sure. "Total zinc additive package" was a point in their pitch.

My 750 clutch didn't care much about oil.  Of course, less drag cold with 10W.Seems like the APTC clutches were fussy, but about slipping, not drag.

Mine had exact same symptoms as you described, this progressed with time to the point when it was not road worthy. Turned out to be a loose clutch basket nut. I also found some other damage - see this topic (http://www.ducatimonsterforum.org/index.php?topic=77443.0) for full story if interested.

I have replaced clutch, engine oil (obviously) and I know everything is within specs, torqued properly and in good shape. Clutch still drags a little bit (bikes not moving really but I can feel it wants to if you know what I mean) and I've tried both OEM and aftermarket slaves. I guess it's one of them things that you just need to live with ;) When mine's cold, it ocassionally stalls when put in 1st, but that's because my idle is set very low (1000 rpm) and as cold engine oil is more viscous, engine dies cos it can't spin with that much resistance on low rpm. It's fine on 1200 rpm (with fast idler lever).

If you still think there is an isuue, pull your clutch. It's easy. You don't need any special tools to inspect it as you don't need to take the clutch basket off!
- get manual, it gives you correct specs and check list
- check clutch pack stack height and all individual plates (warpage, thickness, colour; see manual)
- check the 6 big springs and 3 small ones under the pressure plate (again, refer to manual for specs)
- inspect and grease pushrod (maybe it's bent?), replace orings (they're like £2.50 so just do it)
- check throw out bearing
- check if there are any notches on clutch hub or inner basket, or any obvious damage; if you find something, I would remove the basket and check damper springs in the back of primary driven gear - yes in this case you'll need to buy/fabricate a tool but it's worth doing it as broken springs can cause catastrophic damage
then put it back together and make sure everything is torqued properly