Clutch Drag…

[Mr Gazza]

You shouldn't need the spacer on your 2006 model.
The spacer is to compensate for the shorter early push rods. Your pushrod could also have an "anti-rotation" pin which would certainly confirm it is the later longer type.
It wouldn't work at all with a short pushrod if the spacer was not present.

I'm curious as to what you mean by "lightly re-face the plates" and how you went about that.

[Leamreject]

Originally Posted by Mr Gazza

You shouldn't need the spacer on your 2006 model.
The spacer is to compensate for the shorter early push rods. Your pushrod could also have an "anti-rotation" pin which would certainly confirm it is the later longer type.
It wouldn't work at all with a short pushrod if the spacer was not present.

I'm curious as to what you mean by "lightly re-face the plates" and how you went about that.

It’s a little odd as I dismantled and rebuilt it in the same order, and with a medium dry emery rubbed each face a few times on a flat surface, nothing significant as you would if doing brakes. There isn’t much on them to start with so it was only very light.

It has a non standard billet clutch slave, but I didn’t remove it and when I pulled the rod out nothing obvious came out with it but I’m now getting clutch drag because the clutch won’t disengage fully even on full lever adjustment. If I’d have taken too much off I would have the opposite being clutch slip. It really appears as if it needs more movement.

I’m going to dismantle it again and see if anything obvious jumps out. One thing I did notice is that the plates had little tabs on them and I didn’t spot how they were positioned when I dismantled it. I refitted them in random positions.

[Mr Gazza]

Originally Posted by Leamreject

.. and with a medium dry emery rubbed each face a few times on a flat surface, nothing significant as you would if doing brakes.

I would not.
I don't touch brake pads or clutch friction material with anything other than clutch and brake cleaner and a toothbrush.
The metal and friction material wear together to a near 100% contact area for best performance. Any abrasive interference reduces that and will require further bedding in, not to mention the possibility of embedding carborundum or other particles in the friction material.

Dust is the worst enemy of a dry clutch. Is it possible that some dust remains in the clutch from the emery operation? A wash with clutch and brake cleaner is all it should need. I give mine an annual bath.

Are the slots in the drums worn into little "serrations" where the plates sit? and do the tangs on the plates have any burrs? Those could hold the plates a bit, or tip them, as they will almost certainly have gone back in different slots.

I know nothing about slipper clutches, but I can work out that there is some sort of automatic clutch actuation involved which must have a starting point. Is there adjustment on the slipper mechanism?

[Nickj]

Originally Posted by Mr Gazza

I know nothing about slipper clutches, but I can work out that there is some sort of automatic clutch actuation involved which must have a starting point. Is there adjustment on the slipper mechanism?

Simple back-torque limiter clutch, levels the torque between the motor and driven wheel. Usually a set of 5 or so pairs of ramps _//_ that when you put lots of torque through them slide. The sliding turns the rotation into movement along the axis of the clutch that can be used to push the plates apart a little. Great if you stomp down the gears, the motor doesn't over rev (so much) and the rear wheel doesn't hop (so much) or lock up. Really not fantasticly useful on a road bike but goes with the 'race derived technology' that gets used to advertise bikes, very handy for track days though.
Can be a right royal PIA to get working right.
The 748R has one but it's really crude and was only fitted to homolgate slippers into the ducati race bikes of the time. Besides ii only takes a little finesse to rapidly run down the box as the ratios are so close to start with.

If you have to start grinding away at the clutch with emery or filing the clutch basket where the tangs have made anything more than a smalll polished area then it's a sign from above that it's not well and a visit to your local parts emporium is indicated.