Slave cylinder conversion, 748 to 749

[CCSDUC#100]

Hello everyone!! I have a 2000 748 that I'm tring to convert to the new slave (749). I was told that I could use my standard pushrod with this conversion, but I had to add an 8mm ball to get the length correct. Well, I tried that and I still have no clutch (I can't pull the clutch lever in at all, it's like the piston is out in the slave and is not being pushed in by the rod). I recently put a JTR slipper clutch in, but I don't think this is the problem???

I was told that a 749 pushrod (13.5") would solve my problem, but I wanted to be sure. Also, if I get that 749 pushrod do I then take the 8mm ball out? Any info would be great as I'm getting pretty frustrated (two ducati shops haven't been able to help, in fact one of them told me that the 749 clutch was belt driven??). Thanks in advanced!!

Phillip

[SINJIN]

Welcome to CORNERSPEED and I hope that James can help you out. He has sure helped me in the past and he knows a lot about engines. Good Luck and hope to see you at some CORNERSPEED events.

[CCSDUC#100]

Thanks, this DUC is actually Aaron's old ride. Hopefully you'll see me there this coming spring. I"m tring to save a little money for some races, but we'll see.

[Jim McKenzie]

Unfortunately there isn’t a ‘conversion’ or ‘cross-reference’ chart for these kinds of things, so we have to figure them out. It has been a long time since I have looked at a 748, but we should be able to get you going.

I agree, in that the slipper clutch should not be a problem. Just to be sure though, did the slipper clutch work ok with the stock 748 clutch components?

You said that you still have no clutch…is the clutch engaged or dis-engaged with everything bolted together?

Start by measuring the overall length of the stock 748 pushrod as a reference. Then, with the pushrod installed in the engine, measure how for the pushrod extends out of the engine beyond clutch pushrod oil seal. These will be the baseline measurements we need to maintain with the new components.

Using the above measurements as a guide, install the new components and again measure the how far the pushrod extends out of the engine beyond the clutch pushrod oil seal. This measurement will determine if the 8mm ball will be necessary, or whether you need to go to the longer 749 pushrod.

This should get us started in the right direction anyway. Please let me know what you find out.

[CCSDUC#100]

Thanks Jim, I measured my 748 pushrod (12.75"), I've also talked to a guy from SC who has a 749 (I borrowed his slave and pushrod at the VIR race last season. My slave malfunctioned, hence my delema. This was the last time my clutch worked!!). He measured his pushrod at 13.5". He also told me that there were 2.5" that extend out from the crank. I certainly don't have 2.5", maybe more like .75". It really sounds like my fix would be the 749 pushrod.

Do you know if there is anything that could have slipped out from the clutch side while taking the pushrod out?? I was thinking of disassembling the slipper this weekend, but would love to not have to do that.

Here is the clincher...with my slave off the bike, but still hooked up hydraulically, I can place the pushrod into the slave by hand and get the lever to depress as normal as if there is clutch pressure. Would this suggest that there is nothing wrong with my slave??

One more thing I forgot to mention...the slipper did work fine with the stock components. The reason for the malfunction was a little burr bult up on the slave side of the pushrod which ended up breaking off my aftermarket slave.

The bike is in neutral with everything hooked up.


Your help is greatly appreciated.

[Jim McKenzie]

It does sound like the 749 pushrod is the answer. I would still measure the amount that extends out of the seal with the 749 pushrod to make certain that you don't 'overextend' the clutch when disengaging the first time.

I don't think anything could have slipped out of place by removing the pushrod...make sure that you remove the 8mm ball though.

It's not a definitive test for the slave cylinder, but it does prove that there is not a burr or something to interfere with the action of the cylinder.

It sounds like you are on the right track, let me know how it turns out.

[CCSDUC#100]

THANKS AGAIN, JIM. I'LL LET YOU KNOW WHAT TURNS OUT. CAN YOU RECOMMEND ANYWHERE TO GET THAT ROD FROM?? I'M SICK OF GETTING SCREWED AROUND HERE.

[Jim McKenzie]

If the local dealer doesn't have one in stock (which is not likely) I would order one from Feracci...you will probably have to call them to check availability. The number is (215) 657-1276