Agree re. checking the main nut (though not sure 10nm is correct?), that said I've never worked on a Ducati wet clutch so don't know how they are, but the clutch hub nut on my 916 came loose (after a Ducati dealer replaced the clutch) and the whole clutch assembly worked loose until it actually came off the shaft and ejected itself into the side fairing. As above, I don't know how the wet clutch is assembled but I'm guessing it's not that different to the dry version...
I would look at the clutch slave cylinder and make sure it is moving smoothly, also check if the actuator rod behind the slave cylinder is moving in and out smoothly, the rod seals do wear and could be sticking and the OE slave are not that good - fit an Oberon one if it is sticky. The above is a lot easier than removing the clutch cover.
My MV Turismo used to do this occasionally and made clutch engagement something of a lottery when pulling away from a standstill with, on the rare occasion it did happen, an unpredictable and sudden bite point, could be dangerous when joining a main road for example. Every time I complained to the dealer about it they couldn't find an issue on a test ride. Maybe down to individual riding technique? I suspected it could have been down to a malfunctioning/sticking slipper clutch. I've always been quite dependant on using the gears and engine braking. Bike was eventually moved on for other reasons in exchange for my 1260 Multi. DVT models have a slipper clutch, though I've had no such issues with either of mine.
@Twinlover you're 'thanks' rating just got me the final 'trophy' for this forum. I now have all of them! Thanks!
Everything that you have said about your MV epitomises what is happening with my Multi 1200 DVT. Like you, I enjoy using engine braking along with proper rev matching. On further exploration, I have found that if I work the clutch hard by trying to do a burnout, but pull the clutch lever in and aborting the burnout, then invariably I have no problems with the subsequent moving off. Having said that, there’s no slipper clutch on my Multi DVT.
Numerous other sources agree though probably parroting what's in the Ducati liturature. A slipper effect of sorts can apparently be created electronically, opening the throttle bodies to allow air flow and thus reduce engine braking. Though this wouldn't explain the "Self-servo action on drive" aspect which implies a ramp mechanism. Intrigued to find out the validity of the information in the sales brochure now. If you've ever tried to bump start a Multi, I have, then I might be inclined to agree with you and not what Ducati have said.
I remember clearly the bumping starting experience with you! Halfway along a mountain road with no phone signal and a dead bike… a big relief when it fired up.
Other than the sales brochure I couldn't find official mention of the slipper clutch for the 1200, this video for the 1260 Enduro mentions it though. The illustrations in the workshop manual for both the 1200 and the 1260 show the same clutch mechanism and there are photos showing the ramps on the pressure plate and drum. The following are from the 2015 > 1200 DVT manual.
I think I was getting mixed up with the springs! A timely reminder, if it were needed, to take any advice from me with a pinch of salt!
This is what the hub looks like ! There are many substantially deep grooves worn into it, presumably by the 3 springs. Am I corrcet in thinking these ridges/grooves are causing erratic disengagement of the clutch, creating the sudden clunk and forward progress of the bike on pulling away? Also, how could that have happened ?
If the ramps are smooth I think the groves worn by the springs could possibly be the issue with your occasional grabby take-up of drive. As there's relative rotational movement between the drum and pressure plate giving some lateral force on the springs. This could potentially be the cause of the grooves to start with and also cause the springs to catch and release as the "self-servo action on drive" from the opposing ramps move them against the posts on the drum. A new drum is around £335 inc VAT If the grooves worn into them aren't too deep I might be looking into the option of redressing those posts with a file... The drum is common across quite a number of Ducati models (go here and enter 19610532C) so finding a used one, maybe a complete clutch, shouldn't be too hard. Something like this. Of course with used parts there's always a risk of buying one as bad or worse than your existing one... Goes without saying that you should also be checking the condition of the steel clutch plate grooves on the outside of the drum as well as the friction plate slots in the basket. Any notches worn into those can cause similar gabbiness in the clutch action. Also the smoothness of the clutch push rod and slave cylinder. Though all of these would likely give relatively consistent poor clutch action. The brochure claimed "Self-servo action on drive, slipper action on over-run" is explained in this video.
The basket is grand. I will just bite the bullet and buy a new drum. The 3 springs are out of spec by about 0.6mm so they will be replaced too. Thanks
Odd how the springs have had that much contact with the posts to cause that amount of wear, it looks likely to be the culprit though, bit like a worn basket on a traditional clutch will catch on the plate fingers.
The 'claim' isn't marketing bullshit - I've the same (wet) clutch on my Hyper939. It has a very light action which is facilitated by the self-servo action, plus the slipper works really well Interesting to see those spring-wear grooves tho' I'd assume that'd make the action 'grabby'!
