Hey folks, not long had my engine swapped over to a hayabusa by MK but have been experiencing clutch slip ever since I got it back.

I did think the length of the slave cylinder push rod was too long and holding the clutch out so trimmed it back. All that happened is the piston in the cylinder took up the space and now sticks out a bit when its in its resting position!

So far i've changed the clutch springs, plates, oil (twice!)and trimmed back the slave cylinder push rod and its still slipping! I'm running out of ideas.

Has anyone else experienced clutch slip and what else can I check / do?

Thanks again in advance

Cheers

Iain

Change it to a car engine?

What oil are you using?

Motul fully synthetic, it's the green stuff that smells like bannanas!

Is the rod at the slave returning to its original position on releasing the pedal?

If you open the bleed nipple is there residual pressure?

If you have pressure you could have a problem with your master cylinder.
I had a girling type master cylinder where the seals failed and was stopping the fluid returning.

I also saw another case where a new cylinder was fitted but the master cylinder push rod was too long and this was stopping the fluid returning.

In both cases the result appeared to be a slipping clutch.

As you press down the internal seal covers the hole to the reservoir, at this point it starts to move the slave, if on return you are not uncovering this hole you will be holding the clutch slightly depressed all the time.

Failing that its time for bigger springs or a lockup kit.

Everything i have read about oil for the busa says fully synthetic is a big no no.

Yeah the piston returns to its start position, which sticks out about 3mm from its housing. The only thing I can think of is the cyclinder is knackered and should move more than it does!

I'm going to try opening the bleed, I think there may be residual pressure. The clutch was bled thouroghly the last time I had it apart though.

Well I bought the oil from a local motorbike shop and specifically asked for the correct kind.

I've already uprated the springs (had the same issue with the standard ones) and trimmed back the push rod.

The slave cylinder push rod length should not be a problem unless the slave piston was bottoming out in the slave cylinder.

There is only a very small movement required at the slave cylinder piston (approximately 3mm).

My guess still is that the slave piston is not returning due to a problem at the master cylinder.

If you take off the clutch cover and can't push the push rod and slave piston back against the slight spring action which pushes the slave piston out when it is unrestrained and it only goes back if you crack the bleed nipple then you have a problem at the master cylinder or a blocked line.

As I mentioned before, check that the master cylinder push rod is adjusted so that the internal ports are not permanently covered.
Failing that check that the seals are not displaced.