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 Post subject: 750 Sport & 900SS Technical FAQ
PostPosted: Fri Sep 26, 2008 11:01 pm 
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paso grand pooh-bah
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Joined: Mon Jul 19, 2004 12:00 am
Posts: 1714
Location: Hudson Valley, NY
model: 750 Paso
year: 1988
This thread will NOT be for questions but a compiling of threads that address specific issues witht he 750 Sport model.

17" Conversion Info:

viewtopic.php?f=13&t=2698

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Jon

'88 750 Paso * '87 750F1
'04 Multi 1080s * '88 650 Indy
'65 250 Monza - Moto Giro Project

Click HERE--> 750 Paso Tech FAQ
www.desmoducati.org
www.ducatisuite.com


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 Post subject: Re: 750 Sport Technical FAQ
PostPosted: Sun Nov 16, 2008 1:11 pm 
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paso grand pooh-bah
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Joined: Sun Jul 18, 2004 12:00 am
Posts: 5093
Location: southern Germany
model: 750 Paso
year: 1987
Workshop manual and other downloads:

Ducati 750S:

750 Sport owner`s manual
https://www.box.com/shared/pbgnkjcxlq

750 Sport workshop manual
https://www.box.com/s/s691kou2nhlb3b41bfcy

750 Sport parts catalogue
https://www.box.com/s/7p0bygcer4dy1bvwvl2j

750S wiring diagram in colour
https://www.box.com/s/d95nkk3uis04nzqdato1

750S wiring modifications
https://app.box.com/s/6mqf34acdyjfs9yhrc0m

TÜV Bescheinigungen für Alternativbereifungen (german TÜV approval for alternative tires)
http://www.box.net/shared/5wdgds288g
http://www.box.net/shared/6kbvqrfbh5


Ducati 900SS '90:

900 Supersport workshop manual
https://app.box.com/s/7u0incfpwbpxw1dmyqv4

900 Supersport parts catalogue
https://app.box.com/s/8rb7ayuuif2qs7qncgo5kejzuwld1h3j

900 Supersport frame, swingarm and fork dimensions
https://app.box.com/s/x8e93h3dojj0wq8dzicth2dv2hb6es62

900 Supersport wiring diagram (in colour)
https://app.box.com/s/rqlews1vt1onid6b96bi


other downloads, reviews, magazine articles etc.
viewtopic.php?f=1&t=1551

Paso 750 FAQs you will find a lot more info there! I.e. alternative clutch slave piston, master cylinder rebuild etc.
viewtopic.php?f=1&t=705


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 Post subject: Re: 750 Sport Technical FAQ - Heritage
PostPosted: Wed Jan 28, 2009 4:59 am 
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paso grand pooh-bah
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Joined: Sat Sep 03, 2005 12:00 am
Posts: 1309
Location: SF Bay Area
model: 750 Sport
year: 1990
The 750 Sport was truly a parts shelf bike. It was a bridge between the F1 series and SS series, and borrowed parts from all over. While the A team got to work on the 851, the B team put the Sport together. Fortunately, Verlicchi did most of the development. (they also made the F1 frame) For many of us, its as close to an F1 as we will ever get, and the leading reason to get a Sport.

Even though the Sport was produced for only 3 years, sort of, there are lot of parts that you can still find if you know where to look. But the parts that are truly unique to the Sport are;

- Frame - Made by Verlicchi. sort of similar to the F1. Hey, its cro-moly, and the best reason to own a Sport.
- Swingarm - Verlicchi also. Beautiful, but prone to cracking at the pivot.
- Rear Hugger - in beautiful Polypropylene.
- Body work. Hey, its distinctive. Prone to cracking. Fairings, tank, seat, seat pan,and rear cowl. All paint jobs used the same parts for the series and nothing carries over from or to any other model.
- 4 different Paint jobs included the hideous red/white and blue (Early Europe) the Red and Silver (most common) Black and Silver (same pattern as Red and silver, rare) and the Red and White of the 1990-91 900ss sold only in Europe.
- Forks- Where did they find these things? 40mm Marzocchis with nothing adjustable. Never seen on another bike that I know of.
- Shock - Marzocchi - A marginal step up from the fork, some adjustment.
- Clipons - to fit the 40mm fork.
- Ignition system - Most US models had a single pickup with the Magnet Marelli 2S ignition box. The manual doesn't even acknowledge that it exists, unless you get the ultra rare addition to the shop manual.
- Exhaust system - While it looks similar to the Paso, the headers and the attachment if the silencers are different. The headers of the Sport are the same pattern as SS and Monster headers that came in the following years. I think it had most to do with the Paso's complex rear suspension linkage.

I think that's it. Everything else was shared with the Paso, 851, Pantah, F1 and/or SS/Monster line. Feel free to add to the list of what parts are common to other models, or parts that you have interchanged.

_________________
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.


Last edited by ducinthebay on Fri Jan 30, 2009 8:58 pm, edited 3 times in total.

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 Post subject: Re: 750 Sport Technical FAQ - Common parts
PostPosted: Wed Jan 28, 2009 5:05 am 
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paso grand pooh-bah
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Joined: Sat Sep 03, 2005 12:00 am
Posts: 1309
Location: SF Bay Area
model: 750 Sport
year: 1990
Now, for the parts that are common with other models;

Foot peg assemblies - 851, Paso, sometimes on TT1 bikes
Wheels and brakes - Paso 750 and 906
Rear Sprockets - Paso
Front sprocket - all Ducati with retainer plate
Gauges/clocks, dash - F1, SS line till 98? 851 had same gauges, but also a temp.
Engine complete- Paso 750
Transmission - all 5 speed motors (750,pantah, 620?)
Hydraulic Clutch cover- Pantah, F1, Paso
Side stand - Any Ducati stand will bolt on. All too short.
Coils - Pantah, F1, Paso, SS/Monster
Carb - Paso 750 & 906
Tailight - SS
Mirrors - SS work.
Front fender and brace - Paso and first year 851
Ignition Switch - Paso
Fork bushings - early Monsters (part no. 538028>B)


Afermarket;
Windsheild - Zero Gravity, stock shape.
Seat - Corbin (must be small person to use) (it was in the catalog last year, but isn't anymore)
Mirrors - Emgo
Pegs - anything that fits other Ducatis

_________________
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.


Last edited by ducinthebay on Fri Jan 30, 2009 9:00 pm, edited 1 time in total.

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 Post subject: Re: 750 Sport Technical FAQ- Carbs
PostPosted: Wed Jan 28, 2009 5:43 am 
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paso grand pooh-bah
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Joined: Sat Sep 03, 2005 12:00 am
Posts: 1309
Location: SF Bay Area
model: 750 Sport
year: 1990
Carburetors

The Sport, like the Paso, came with a 2 barrel Weber carb adapted from an automotive application (1200cc Fiat?). Needless to say, it had some issues. It was a good idea, it was just implemented badly. Further proof that the Sport was a parts bin bike and the development team had no time to finish complex problems like proper carburation.

The biggest problem was that the fuel pump was too strong for the needle jet in the carb, thereby flooding it, all the time. Putting in a pressure regulator at 3psi improved things imensely. There were a few other tweaks you could make to get the stock carb working reasonably, but 'reasonably' was all you could expect. There was a whole lot more potential in the engine if you change out the carbs.

In the Paso, you could bypass the fuel pump, but you can't do that in the Sport. The fuel lines in the tank are brazed in such a way that if you take out the fuel pump, you will only use 1/2 of the tank's capacity. Not a good option. Make sure your fuel lines have a T in them that returns to the tank. This keeps your fuel pressure reasonably low and won't flood your carbs. The return line is one of the stubs in the middle of the tank. One is a vent, the other is a return.

The first aftermarket carbs that were available were the 36mm Dellorto carbs with either the Mallossi short manifolds, or some from a Pantah (grab the whole setup if you can). You need to get a duel cable throttle twist grip. The Tommaselli Daytona 2S it the best choice (probably the only choice). The 36mm carbs work the best on the street. The old F1 had 40s on it, which made it a dog on the street, but good on the track. Don't be tempted to put the 40s on, it won't be an improvement from the 2 barrel Webber. They are way too big and you wont like you bike. (good for a 900 though)

I've been sneaking up on the jetting on my 1990 Sport.
Current jetting in my 36 PHM Dellortoswith 2into1 exhaust
160/162 main (richer in back)
60 pilot
265 atomizer
K5 needle in middle postion
60/4 slide
Champion plugs

Some others are running a 261 atomizer, also known as the needle jet or needle seat, They also run a bit fatter needle, like a K27. For some reason, The jetting I have seen posted are all over the place. Some people are running a 135 main, which my bike ran horribly on.

The intakes for the carbs get awfully close to the rear cylinder, and the battery. Air cleaners just don't fit well. I put the Dellorto grey plastic screw on bells (velocity stacks, intake runners, whatever you know them as), and attached 2" rubber elbows that allowed me to put some UNI air filters sticking straight up into the area where the stock airbox used to be.I bought them from http://airflowonline.com/ , the part number is 90HL2 Rubber Intake Hose 90 Degree 2" less than $10 each.

Adding a bit of length between the air cleaner and the carb vastly improves low end performance and torque. There's a phenomenon called fuel fog that comes back out of your carb at lower rpms. If you don't contain it, it becomes a variable mix, sometime too lean, and sometimes too rich. There's also the complex topic of laminar flow and Helmoltz resonator. Without getting into complex intake design and fluid dynamics, trust that adding just a few inches of intake trakt will make the bike run much better, all the way across the range. This is one of the functions of a stock airbox. Race bikes historically didn't use an airbox because they are rarely using the low end, but a street bike does all the time. If you run straight air filters, try and stuff the longest velocity stacks into it that you can fit. ( I just read that one of the big changes to Casey Stoners bike this year is a new airbox to improve midrange)

The other popular carb swap, and much cheaper, is to grab a used set of stock carbs from the Monster or SS line (91-98) They are Mikunis, and are tied together, so you keep your single cable throttle. Make sure you get the intake manifolds to go along with it. If you grab some from a 900, it will pretty much run straight away. The 750 carb set, while basically the same, will need a bit of jetting change to get it work at its best. On the Sport, this carb system is aimed right at the battery, so air cleaner options become a bit limited. Someone posted a picture using the plastic plumbing of a J-Trap, which I thought was rather creative. I haven't heard of anyone adapting a stock airbox to the Sport, but if you have the time and parts, we would all love to know how that works.

The high performance option is the flat slide Keihin FCR carbs. Since they are the popular option for the SS and Monster, they are in demand and you won't find them cheap. They will run almost $1k new, but you will find a lot of people who know how to set them up and will be able to help you get them jetted correctly. Its also the easiest option to buy new, and get what you want. Again, air cleaner options become limited, and you need to become creative. This is the best option if you have the money.

_________________
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.


Last edited by ducinthebay on Wed Jan 28, 2009 6:38 am, edited 1 time in total.

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 Post subject: Re: 750 Sport Technical FAQ - Front Brakes
PostPosted: Wed Jan 28, 2009 5:54 am 
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paso grand pooh-bah
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Joined: Sat Sep 03, 2005 12:00 am
Posts: 1309
Location: SF Bay Area
model: 750 Sport
year: 1990
Front Brakes

The standard F08 brake calipers were adequate for the time, but newer brakes are much stronger. First Brembo came out with the 32/32 4 piston calipers that were black and came on the first year 851 and last year 907. Then they quickly went to the P30/34 4 piston caliper with is gold colored and so prevalent through most of the 90's and up to the introduction of radial brakes. They offer a lot more stopping power, and there are a host of brake pad choices available, although I still prefer the EBC HH pads.

The biggest problem in using the newer calipers is that the mounting holes don't line up. Not even close. But there is help. A caliper adapter.
http://www.roadandrace.com.au/cat17.htm
You can also find the CAD file for them on Baukes Paso page, if you have access to a CNC mill and a few chunks of 7 series aluminum. I followed this option with some machinist friends, and it worked out wonderfully.

If you do a 17" wheel conversion, then you definitely want to make this modification. Since both of the adapters mentioned are for 280 or 300mm rotors, you will need to find some rotors also. 300mm Brembo rotors came on the early 851, and the 91 907, so they are kind of rare, but oddly Ducati re-introduced them on 620 monster. An easier rotor to find are the Yamaha ones, which have the same bolt pattern and offset. Search for FZR, YZF, and TDM. They also are still being used on many of their cruisers. Make sure they are the smaller hole pattern in the middle, as they changed them around 2000. You can also find them on the EBC site in steel, or if you are lucky, some old Brembo cast iron.

If you make the change to the 4 piston calipers, you must also change your master cylinder to a 16mm piston type. These are cheap and plentiful on e-bay.

Better brakes make a world of difference. Well worth the upgrade if you are handy, but certainly a handful of work if you are not too handy.

Cheers,

_________________
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.


Last edited by ducinthebay on Sun Jul 10, 2011 4:01 am, edited 1 time in total.

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 Post subject: Re: 750 Sport Technical FAQ - Forks
PostPosted: Wed Jan 28, 2009 6:15 am 
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paso grand pooh-bah
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Joined: Sat Sep 03, 2005 12:00 am
Posts: 1309
Location: SF Bay Area
model: 750 Sport
year: 1990
The stock fork is a Marzocchi M1B, with 40mm legs, which are adequately stout, even to todays standards. They seemed to work OK, as there isn't much whining and winjing about them from the populus, and the original reviews in the magazines seemed to like them well enough. The down side is that they have no adjustments at all, at least in the modern sense. You can change the springs and the preload, the old fasioned way, by changing the parts. HyperPro makes a spring for the Sport. Likewise, you can change the damping by changing the oil weight. If you want more compression damping, or more rebound damping, then you have to know how to take the forks apart and modify them. So basically, if you like the way your fork works, be happy that what you have works for you.

If your fork is shot, or you can't find a happy medium with it, there are alternatives. Both involve a new front end.

Door #1
Paso front end. Get the Marzocchi M1R fork with compression damping in one leg, and rebound damping in the other. Ideally, just get a set of Paso forks and triple clamps. The forks will fit right up to your frame and your front wheel and brakes. The only trick is the clip-on handlebars. The M1R is 41.7mm, which is a supremely odd size, and you won't find clip-ons to fit, except from a first year 851 (good luck). You will need to machine them. TeleFix or Tomasseli's have aluminum clamps with enough room to machine. In general, nice forks, same geometry, same look, better damping control. HyperPro also makes a spring for the Pasos. Be aware that the Paso forks came in different lengths. The 750 and 907 were the same length as the Sport, but the 906 was shorter by 10mm. Also, the 907 fork used the newer calipers and 17" wheels. This is the one route to changing your bike to 17"s The 851 fork had different damping (better) but it is another 10mm shorter than the 906, so its really short, but will work on the Sport, but also had fork mounts for the 4 caliper brakes, which is a big bonus.

Door #2
A whole new front end. USD (upside down forks) and be done with it.
The SS front end fits nicely as a few have proven, or even a Superbike front end. I even heard of someone using an entire GSXR or YZF front end. Get the wheel, brakes, bars, triple clamps and all. Pain the ass? Depends on how handy you are. Worth it? All who have done say so, but after all the trials and tribulations they wouldn't say otherwise. Your biggest challenge is fitting the triple clamps to your frame. When you are done, you have modern suspension, modern wheels, modern brakes, modern rubber, all good things. The one thing to check in getting a full front end is the offset of the forks to the steerer tube. Less offset will slow your steering, which the Sport doesn't really need, but its hard to find an offset less than the Sport. A larger offset will quicken your steering, but loose a bit of high speed stability. for a point of reference, the first year 851 had the M1R forks, but had 3mm more offset in the triple clamps.

Check out loudbike.blogs.com/ for his write up of the 'Cadillac'. He took a perfectly good Sport, and a kind of haggard 900ss and built the "Cadillac". He explains how he set up the suspension on that Sport frame.

With the Sport, there is always the debate whether you should keep it stock, or modify it. If you have a nice example of a stock bike, I say try to keep it that way. There are so few of them around. If, like my bike, there was little left to salvage, modify to your hearts content, or your pocket book will allow. I can't forgive LoudBikes for taking a perfectly good Sport and scattering the parts across the country, but I have to admit I bought parts from him when he did that. To his credit, he wrote about it so that maybe one of you will benefit from his expertise.

Cheers,

_________________
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.


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 Post subject: Re: 750 Sport Technical FAQ
PostPosted: Mon Mar 01, 2010 11:27 am 
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paso grand pooh-bah
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Joined: Sun Jul 18, 2004 12:00 am
Posts: 5093
Location: southern Germany
model: 750 Paso
year: 1987
documented total rebuild

viewtopic.php?f=13&t=3829


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 Post subject: Bleeding Clutch
PostPosted: Sun May 30, 2010 1:37 am 
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Joined: Mon Mar 24, 2008 1:40 am
Posts: 15
Location: USA
model: 750 Sport
year: 1990
Bleeding the clutch

My twin 750 Sports sat for two years and the clutch levers were limp. I tried bleeding as described in the service manual, but pumping the clutch lever wasn't happening. I read a few posts where some of you used vacuum bleeders, but I didn't want to go out and buy yet another seldom-needed tool.

So, I made a pressure bleeder. Clutch bleeding took about 5 mins. total.

Here's some pics:

Cut a piece of 1/4" plexiglas a little larger than the top of the MC. Drill a hole in the middle and used JB Weld to secure a 3/8" vacuum fitting.

Affix a piece of rubber/gasket material to the mating surface.

Clamp cover to top of clutch master and attach hose from pesticide sprayer filled with brake fluid.

Pump it up and operate the bleeder screw down by the slave.

Pump the clutch lever a few times to test. You will get more air bubbles out doing this. Keep the pressure on from the bug sprayer and keep pumping the clutch lever until no more bubbles. You'll feel the lever getting harder.

Close the bleeder, release the pressure from the bug sprayer. Carefully un-clamp the bleeder adapter (MC may be overfilled...be prepared with rags).

That's it. 5 mins. total bleed time with minimal effort. :choo: :choo:

P.S. - You can use this same device for bleeding brakes, too (motorcycles & cars).


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 Post subject: Re: 750 Sport Technical FAQ
PostPosted: Sun Dec 01, 2013 7:50 pm 
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paso grand pooh-bah
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Joined: Sun Jul 18, 2004 12:00 am
Posts: 5093
Location: southern Germany
model: 750 Paso
year: 1987
750S wiring mods

https://app.box.com/s/6mqf34acdyjfs9yhrc0m
The file preview may show some pages very small. Download the file then.


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 Post subject: Re: 750 Sport Technical FAQ
PostPosted: Sat Feb 28, 2015 6:05 pm 
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paso grand pooh-bah
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Joined: Sun Jul 18, 2004 12:00 am
Posts: 5093
Location: southern Germany
model: 750 Paso
year: 1987
900SS conrod small end bush

viewtopic.php?f=13&t=6839


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 Post subject: Re: 750 Sport Technical FAQ
PostPosted: Sun Jul 19, 2015 7:40 am 
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paso grand pooh-bah
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Joined: Sun Jul 18, 2004 12:00 am
Posts: 5093
Location: southern Germany
model: 750 Paso
year: 1987
service bulletin gear selector mechanism - all Ducati

https://app.box.com/s/ccqi4o1hoelpn458dffawwf51kiq20cs


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 Post subject: Re: 750 Sport Technical FAQ
PostPosted: Mon Jan 16, 2017 10:10 am 
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paso grand pooh-bah
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Joined: Sun Jul 18, 2004 12:00 am
Posts: 5093
Location: southern Germany
model: 750 Paso
year: 1987
turn signals

viewtopic.php?f=13&t=7642


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