Q: Bevelhead Ducati. How to free-up a binding clutch?

[jim.cox]

Ok, I'll be the first to admit it: The MHR does not get enough riding.

Aside from a WoF and new a front tyre there isn't actually much holding it back.

Except the clutch - which is binding (again).

I've pulled it apart before and found parts of it are so polished that with the 50 weight oil they virtually vacuum themselves together.

So whats the recommended cleaning and loosening treatment for a ducati clutch, and do I rough it up a little with some steel wool or something?

Cheers,

Jim

[Laava]

Not too badly notched into the fingers of the clutch basket?
On that, I remember mine being a basket! Hard to find N at the lights and very heavy.

[OddDuck]

+1 - have a look at notching. The basket is likeliest but also check the hub. Frictions and steels should be able to slide axially on both without interference. Also worth checking for sharp edges on steels, if these are digging in on hub splines then that can be part of the problem.

Something worth a look at is release travel. I found on the dry clutches that owing to plates being a bit springy and not perfectly flat, that around 2mm of clutch actuator travel was needed to get them to release properly. On that note... check your pressure plate for cracking. If its similar to the high zinc alloy found on the belt drive bikes then it'll be cracked after mileage and will be flexing badly under load, ie not releasing properly.

Polished surfaces locking up under oil isn't one I've dealt with before (dry clutches only on both my bikes) so pinch of salt here - maybe put the steels onto a flat plate, with some 160-grit paper down, and lightly rough them, taking care to rotate every once in a while so you get even coverage?

[Voltaire]

What they said.
How old are the drive plates?
You can get a longer actuator ( lever that sticks out top of rh cover or as I did convert a ducati belter clutch ( you can buy custom ones but 500 us from memory)
Levels are not known for ease of finding neutral.
They however are fun to ride and sound great

Unrelated but replaced the old friction plates in my Commando and it transformed it, light, no drag, readier gear changes.

[F5 Dave]

Front wheel against a wall, 4000rpm, clutch in and Slam it into gear and . . . .




it was just a suggestion

[Voltaire]

Front wheel against a wall, 4000rpm, clutch in and Slam it into gear and . . . .




it was just a suggestion
“ .... ran when parked up, may need gearbox work due to bodgy repairs by previous owner ( see above)”

[jim.cox]

Hey cheers for the input lads.

Hope to get that clutch sorted this weekend.

"glazed" was the word I was thinking of...

[Kickaha]

and do I rough it up a little with some steel wool or something?

I always used to bead blast steel plates in any clutch I had apart

[F5 Dave]

I find real smooth flat concrete and figure 8 the steels. Then brakeclean.

[kiwimacchi]

I imagine the clutch is the same as the Darmah?
From memory, my Darmah had about an 8 piece push rod (including balls)- I had all sorts of issues until I replaced it with a 2 piece rod with 1 ball between rods, as the drilling between crankcase halves wasn't straight! Maybe Ducati only had short drill bits when they were building these motors?
I also converted it to hydraulic operation using a complete VT250 Honda setup. Took about an afternoon- I replaced the LH original cover with a piece of Ally (10mm) to mount the slave cyl on. Worked a treat and never had any more issues with it.
Remember when I sold the bike, I got all the 'experts' commenting on the conversion!! Bloody wankers.

[jim.cox]

Well, that hasn't gone so well...

The previous weekend I stripped, cleaned and repacked the clutch. Nearly, but not oh so not quite, got her running.

This past weekend I drained the tank and cleaned taps and lines.

I kicked her over - and found that when I put her in first, even with the clutch pulled in, the engine is trying to turn over...

[F5 Dave]

That makes little sense, or rather I don't understand.

So later ducs were dry clutch, these are wet yeah? There will be a decent amount of drag when it is cold and in gear.

I'd warm it up nicely and try again.

Failing that take it for a ride crash starting it, ride it and see if the clutch is freeing.

So when you rebuilt it did you try pull the clutch and see that it rotates? if you can do that with cover off, I'm presuming a far side pushrod rather than a near side pull .
Did the pressure plate move ok?

[jim.cox]

That makes little sense, or rather I don't understand.

Yeah, that's what I said.



So later ducs were dry clutch, these are wet yeah? There will be a decent amount of drag when it is cold and in gear.

Yes, wet clutch same as 900SS and Darmah.

They are a heavy clutch, but I would have thought that I should be able to push the bike in 1st, clutch in and not being turning over the motor against the compression.

At the lever the clutch feels normal, and the whole shebang does move. But I like the idea of checking and lubing and the actuation rods, it must be 20 yrs since I was last in there



I'd warm it up nicely and try again.

That was my thinking. Pumping some warm oil over those fresh plates may well help.



Failing that take it for a ride crash starting it, ride it and see if the clutch is freeing.

Got to get her started first...


So when you rebuilt it did you try pull the clutch and see that it rotates? if you can do that with cover off, I'm presuming a far side pushrod rather than a near side pull .
Did the pressure plate move ok?

Yes to the above, but I did note the pressure plates seem worn at maybe 3.6 - 4mm thick. That I would have expected that would lead to slippage, not locking up.

Nevermind, I'll try kicking her in guts again this weekend...

[malcy25]

On bikes that I have had with both dry and wet clutches, I've had plates that stick together.

One memorable situation was my 125GP that you bumped it by rolling it in neutral then hooking a gear.....and hope it fired, then once running with the clutch in and some front brake, blipped the throttle and it would break free....except when the neighbour has just cut the grass and it's all over the foot path and it's night and you don't see it. Grazes healed in a week or so....

I've found some wet clutch bikes just have more clutch drag too, which when trying to bump them will cause surprising amount of drag.

On my GP bikes with dry clutches, washing the bike would make the plates stick and be a small pain, but would free reasonably easily, most of the time, but the expensive one with the weakest clutch happens to be the worse to free up.....

If you are getting the required lift of the pressure plate, more lift won't cure your problem.....as mentioned, doggy hub and basket won't help. But sticky plates will do it too.

[malcy25]

I find real smooth flat concrete and figure 8 the steels. Then brakeclean.

I bought a marble cheese board from Stevens kitchenware shop! :laugh:

[sidecar bob]

I bought a marble cheese board from Stevens kitchenware shop! :laugh:

I re corked a Jawa clutch with cork table placemats from the warehouse.

[Kickaha]

I re corked a Jawa clutch with cork table placemats from the warehouse.

I wouldn't expect anything less from someone who'd take a grinder to front brake discs :msn-wink:

[F5 Dave]

I bought a marble cheese board from Stevens kitchenware shop! :laugh:
Ohh, how very grandiose :cool:

You can make cucumber sandwiches at the race track on the other side.

[sidecar bob]

I wouldn't expect anything less from someone who'd take a grinder to front brake discs :msn-wink:

Have you suffered a head injury too?

[Kickaha]

Have you suffered a head injury too?


It's about the only part of me I haven't injured

[jim.cox]

Finally

Finally

Finally

I managed to make some time to kick the old girl over.

Took quite a bit to get her started - always does if she has been sitting.

Best yet, the clutch freed up once the oil was warm.

Thanks to all for their advice and encouragement.

[Bonez]

Good stuff. Fuel can go stale over time. If I leave my bike for a while the first thing I do is drain the carbs and open the fuel tap and let it drain for 15 seconds or so before even trying to start the bike. The concrete wall trick for freeing up stuck clutches if it's been sitting a long time works a treat I've found in the past. If you have't got a file or sandpaper handy a moderately rough congrete surface will help tidy them up. A mable cutting board on the other hand just looks pretty. On second thought it could be used a baddock plate.

[husaberg]

I re corked a Jawa clutch with cork table placemats from the warehouse.

Did you boil them to expand them pretty sure they used to do that also after they were fitted?
Although that might have been as they used to use the ones from the Vino
I remember watching the old man doing one whan i was about 5 on a villiers i think.