1988 750 sport

[mickyfinn]

Hi guys, im new to here, just picked up a 1988 Ducati 750 sport 11000km in mint condition, has obviously been dropped at some stage as the fairings dont have the original blue decals on them, a big thank you to Paso750 grand poo bah, we are truely not worthy of you oh great one,for information on where to source a clutch from http://www.stein-dinse.biz/Ducati/Clutc ... 2_739.html, i spent at least 10 hours hunting around on line, went to paso750 poo bah's reccomended site, and voila there they were.

Bike starts and runs fine but i notice when stopped at the lights, the clutch is grabbing and nearly stalls, also difficult to get into neutral. Have done a hydraulic oil change and adjusted the clutch lever to the full extent, no oil leaks at either end. The clutch plates do have scoring and pit marks on them, may try rubbing them with a bit of wet and dry sandpaper.

Any ideas would be much appreciated, hydraulics or clutch plates/springs. What do you reckon ?

Regards

Mick

[ducinthebay]

Mick,
Welcome to the site. As you have mentioned, lots of great information here, and some outstanding contributors.

One thing to check is if you have the correct master cylinder on your bike. Old bikes are always suspect as parts get replaced by previous owners. Then also see that you are getting full travel from the lever and the master cylinder piston. Eliminate any free play, which sounds like you have done.

Then take the clutch and plates all apart and confirm everything is correct, which it sounds like you have had one pass through it. Confirm the center nut is tight on the clutch basket and you have the correct stack height, and order of the plates. Definitely take the slave piston out of the cover and clean it up. There is an amazing amount of crap that ends up in that bore after the years.

All of your symptoms indicated a clutch that is not disengaging completely. It also sounds like nothing is terribly wrong. Just taking everything apart, and setting it right will most likely solve things.

Cheers, Phil

[bmw851]

G'Day Mick,

Have a trawl through all of the various topics if you haven't already, some fascinating reading on this site, now know more about the different Paso's than I ever wanted, and don't even own one, and as to the Sport well what can you say.

Even without a dickie clutch, neutral seems to me to be near impossible to select when stopped with the engine running, but not a problem if you can nick it in while on the move just before stopping, not always possible, but a habit maybe worth getting into with owning one of these little treasures.

(And mine has done just under 6,000km and is still a pain to get into neutral)

Welcome to the site.

Cheers
Peter

[mickyfinn]

Mick,
Welcome to the site. As you have mentioned, lots of great information here, and some outstanding contributors.

One thing to check is if you have the correct master cylinder on your bike. Old bikes are always suspect as parts get replaced by previous owners. Then also see that you are getting full travel from the lever and the master cylinder piston. Eliminate any free play, which sounds like you have done.

Then take the clutch and plates all apart and confirm everything is correct, which it sounds like you have had one pass through it. Confirm the center nut is tight on the clutch basket and you have the correct stack height, and order of the plates. Definitely take the slave piston out of the cover and clean it up. There is an amazing amount of crap that ends up in that bore after the years.

All of your symptoms indicated a clutch that is not disengaging completely. It also sounds like nothing is terribly wrong. Just taking everything apart, and setting it right will most likely solve things.

Cheers, Phil

Thanks heaps Phil, took the clutch apart cleaned the fingers with emery, cleaned the piston, discovered the second plate was reversed, it looks like it has a bit of a dish in it, clutch is working a lot better now, not sure what the stack height is meant to be though, i have a new clutch on the way courtesy of Barnett California, then i'll have some spare plates to play around with. Still seems a bit clunky changing gears with the clutch master adjusted to full extent, not as smooth as i would have expected, but i'll see if changing the stack height makes any difference, dont think it will do any harm.

Thanks for the tip

Micky

[mickyfinn]

G'Day Mick,

Have a trawl through all of the various topics if you haven't already, some fascinating reading on this site, now know more about the different Paso's than I ever wanted, and don't even own one, and as to the Sport well what can you say.

Even without a dickie clutch, neutral seems to me to be near impossible to select when stopped with the engine running, but not a problem if you can nick it in while on the move just before stopping, not always possible, but a habit maybe worth getting into with owning one of these little treasures.

(And mine has done just under 6,000km and is still a pain to get into neutral)

Welcome to the site.

Cheers
Peter

Thanks Pete,
Whats yours like changing through the range, mine seems a bit clunky, i'm going to have to work on that i think. Your'e right i have learned somuch from this site already.

Mick

[paso750]

Mick, adjusting the clutch lever at the master pump is the last thing you should do if you don`t find the actual problem. Properly bleeding the clutch is not easy so one of your problems may be some remaining air in the clutch line.
Another reason could be that the clutch doesn`t properly disengage because the clutch basket or the core has rattle marks.
If you start mixing two clutch packs do mark the discs from one so you always now from which the discs come from.

G.

[bmw851]

Hi Ya Mick,

Wouldn't call it smooth, but definately not clunky except for engaging 1st, find it fairly typical for a late 80 early 90's Duc, rode an S2R 800 & a S4R 916 Monster the other day and the shift changes felt fairly similar, little bit more forgiving and didn't have to be as precise with whole foot/throttle/clutch timing but all over you knew what you were riding a Ducati.

Cheers

Peter

[ducinthebay]

I have no trouble with mine. I can easily find neutral at a stop, and it shifts as well as my ST4s. When I built up the bike 5 years ago, I went through the entire system and installed a new braided hose. I must admit, it took quite a bit to get that thing bleed out correctly. That cover is bitch. Use a vacuum bleeder, it seems to help. A little bit of air will create all the symptoms you mention.

Cheers, Phil

[Mc tool]

I only ever had any real success bleeding that bleedin clutch by reverse bleeding it .... forcing fluid into the slave bleed nipple and right up into the resivior and then fitting the resivior lid , turn the bars to the left and give it one more bleed by cracking open the bango bolt at the resivior ( use rags to catch fluid ) as a bubble can hide there too

[mickyfinn]

Thanks Ducinthebay and mctool, will give both methods a go.

Cheers

Mick

[bmw851]

I have no trouble with mine. I can easily find neutral at a stop, and it shifts as well as my ST4s. When I built up the bike 5 years ago, I went through the entire system and installed a new braided hose. I must admit, it took quite a bit to get that thing bleed out correctly. That cover is bitch. Use a vacuum bleeder, it seems to help. A little bit of air will create all the symptoms you mention.

Cheers, Phil

Thanks Phil,

Guess I'll have to get around to finally bleeding it then, bugger thought had got away with that one.

Cheers

Peter

[Mc tool]

Another thing to check for is a sticky black shit on the plates ..... if either of the oil seals are weeping oil will get onto the clutch plates and burn on ( black shit ) and it can make the clutch really grabby and draggy ( engage abruptly and not disengage completely...... and this can manifest itself by suddenly feeling like the bike wants lurch forward a foot or so while at a stand still ).The seals are are really common ( cheap ) and are easy to get at .... if in any doubt just change em
When the clutch is bled properly , has good clean plates ( no oil residue ) and has a good release bearing ( see F A Q's ) they are a good clutch for a standard engine . I have often seen comments re the wear on clutch baskets and plate tangs causing problems .... but I gotta say the ones on my SS are really BAD ( want a pic ? ) yet the clutch functions perfectly when everything else is right

[mickyfinn]

Thanks MC, definiteley no oil in there, so i'm going to focus on the hydraulics and iv'e got a new set of plates on the way from Barnett, thanks heaps for the tips, where you from, i'm ex Rotovegas, living on the Gold Coast now.

Cheers Bro

[dukefan]

Hi have recently bought a 1989 sport, had roughly the same Kms on the clock and suffered the same clutch problem as yours, got a replacement clutch bearing from Stein Dinse, had a problem that the rubber seals in the bearing had deteriorated but after they were replaced the clutch has been good [haven't heard of this model ever having a great clutch]
They are a great bike, I love it.
Cheers
Rob

[ducinthebay]

Hmm. My clutch has always worked really well, and not near as finicky as the ST clutch. My sample size is one, so I don't know if I'm lucky, or what. The rest of the bike was all done badly and needed work.

Start from the basics. take everything apart, clean it up, make it back to stock, then see what you have.

If you have the old rubber hose leading to it, those are often suspect after 20 years. Get your self a new hose to ensure that there is no blockage.

Cheers,

Phil