Clutch Slip

What I really don't get is why adding a thicker plain plate is going to help.
I'm the first to admit I know sod all about slipper clutches but I will be amazed if this helps.

 

The spider spring should make no difference to stack height, it only affects the preasure on the center hub rising up the ramps.
Steve

 

So if clutch was fine after you doing spider and greasing balls would that say clutch stack height and operating clearances was good then ?
It's only gone wrong since doing cylinder ?

 

Can you measure your original slave cylinder fully compressed (where the pushrod seats) to the face where it bolts to the engine casing and do the same with your new master cylinder.

This will answer all the questions in relation to the clutch slip side of things, presuming you are still using the same release pushrod.

If you can push the new master cylinder fully onto the casing with hand pressure only then odds on it isn't preloading the release button whick would cause slip.

As I said before though if 1mm is the difference between slip and poor clutch release/ drag you're either not going to have enough pressure on the plates or you'll have drag as the clutch warms up.
I don't recall ever seeing a clutch with a 1mm release action, more like 3mm to 5mm. That is where all your problems are coming from re dragging and poor neutral selection.

With the clutch hot, you need to ensure there is no pre-load on the release pushrod.

 

As another idea, have you checked to see if the slave is faulty in any way despite being new. Do you have any form of slow leak or trapped air bubbles in the line or elsewhere

 

can the plates in anyway be partly seized in the basket and not allowing it reseat?.
i liked Chris's original technique for checking if its the slave

 

doh, read the whole thread fin.
i test car clutches by slipping in to top gear, pulling on handbrake covering the brake and throttle with me right foot and dumping the clutch. can this be done after you have backed the slave out a turn or two?

 

Try bleeding the clutch "uphill" or use a pressurised bleed setup (Halfords!) and see if any air comes out.

If you have the clutch on your 999 apart and the friction plates are the same type, alloy or steel, then you could try mix and match on those.

I cant help thinking that there is something here which is either upset, not seating right, has air in it, etc.etc. that is causing this problem..It could be quite minor but still enough to throw the clutch out and stop it operating correctly.

Have you tried checking the clutch with the lever pulled in and rotating the wheel on a paddock stand that allows the rear wheel to turn over freely enough for you to see and check what the clutch throw action is like?

 

Standard steel part numbers -

• 19010011A - 2mm
  
• 19010231A - 1.5mm
  
• 19010242A - 1.5mm (Convex)

 

Air in hydraulics would cause poor clutch release but would have no bearing at all on the clutch slipping..

 

You could try the cable tie overnight trick to see if that helps you find neutral.
If it works, it may not be permanent but at least you'd know it was air causing the problem

 

It took a bit of faffing with different clutch plates to allow neutral at standstill on mine.If you have no slip then just try swopping a 1.4 for a 2mm plate.