Clutch Problem
 

My clutch has just started playing up on my 999 2004 but I believe it is the same as all the other models. The lever action is perfect until I have cause to hold the clutch in for fairly long periods ie. 1st gear in heavey traffic. Then the clutch 'biting point' gets progressively nearer the bar until finally the clutch drags and prevents me from selecting neutral!

At this stage if the lever is released and pulled back a few times the clutch behaves normally again until the next time I need to hold it in for a while.

I have removed the slave cylinder. The clutch push rod and inside the bore of the slave are wet with blackish oil, everywhere else is bone dry.

Does this mean the master or slave cylinder needs bleeding (bleed nipple in the master cylinder on the 999) and is this just a temporary cure or that the slave cylinder oil seal has just started to leak and needs replacing or both or something else.

Thanks

If the pushrod is spinning because the bearing in the clutch pressue plate is not perfect, the rotating pushrod will cause the piston in the slave cylinder to gradually back-off, resulting in the symptoms that you have.

Large bore aftermarket slave cylinders are more vulnerable to this, as the travel of the pushrod is less.

Spin

If it is just pushing the piston back, presumably forcing the oil back into the master cylinder why is the push rod wet?

The fluid in the actuating system (slave cylinder) should remain completely separate from the pushrod itself. I think any dark oily fluid found on the pushrod is more likely to be engine oil. The pushrod has o-rings on it, and one might expect it to need lubrication. Someone with greater knowledge than me can confirm whether the pushrod is exposed to the internal oil of the engine, I'm sure.

I had the same persistent problem with my clutch lever "going-off" at track days. I probably spent several days in total bleeding the system.

Recently, LougiMoto serviced my 998 (Evoluzione slave cylinder), including clutch bleed, clutch re-stack, grease pressure plate bearing. At the next trackday I had consistant and perfect clutch actionthroughout.

Spin

The idea of the o rings on the push rod is to stop engine oil coming out of the engine. Between the two o rings you should have clean engine oil. At the slave cylinder end of it then you will find a mixture of chain lube and clutch fluid if you have a slightly leaking cyclinder. Clutch fluid and engine oil have very different smells so give em a good old sniff.

My wife thinks I spend too much time with my bike as it is. If she catches me sniffing its private places, I don't know what will happen.

Spin

Thanks for the replies. I checked last night and found the push rod wasn't spinning.

The only wet area, that I remember seeing, was inside the slave cylinder bore so I reckon it must be the seal. Anyway, I have booked it into Parkinson M/cs for them to sort it out. I intend useing the bike for the BSB at Sneterton so I hope it holds out.