1989 750 Sport Project - Any Suggestions?

discussion about the 750 Sport and '89/'90 900SS, which share many mechanicals with the Paso series
bobbyb13
Posts: 5
Joined: Sun Jul 17, 2011 4:11 pm
model: 750 Sport
year: 1989
Location: West Midlands, UK

1989 750 Sport Project - Any Suggestions?

Post by bobbyb13 »

First of all I'd like to say hello to all fellow sport owners, wherever in the world you may be.
What a brilliant resource of knowledge, wisdom and expertise this site is, I'm very happy to have found you. I have a 1989 750s purchased at the start of the year, I was hoping to get it ready by summer but have only just got round to making a start (you know how it is). I'll give you a few details so you know what I'm dealing with:

Pictures: http://s1179.photobucket.com/albums/x38 ... rt%201989/

1989 750 Sport (european import)
31,000kms
7 previous owners (the length and breadth of the UK) perhaps you used to own this machine?
Previous owner(s) had modified the bike in order to replicate a 750 F1 (paint job, decals, etc)
16" wheels
40mm dellorto PHM carbs
tommaselli daytona 2s throttle
aftermarket 2 into 1 stainless exhaust system (no brand)
dry clutch
standard forks and rear shock

Good points:
The bike had not run for a few years when purchased and before being stored was equipped with brand new...
16" michelin tyres
chain
38t sprocket
brake pads
braided clutch and brake lines
engine oil is clean


Bad points:
ELECTRICS!!! (see pictures in link)
Frame has been butchered
Fuel pump removed from tank

So Far...
Started it up about 2 weeks ago, it ran on one cylinder and sounded rough as hell. So...

Stripped and cleaned the carbs and ran it up again, it runs sweet! Not ridden yet but it starts, idles and climbs through revs as you would expect. A change of belts and engine oil is all I shall do for now.

I'm currently converting to 17" brembo wheels with 4-pot calipers on 320mm discs. I have gathered loads of research from this site, many thanks to those contributors. (I may upgrade suspension in future if using it on track)

My main problem is the electrics and what the hell to do with them?
If you look at the pictures in the link you will see that everything electrical has been relocated/rewired and is in a bit of a state (aesthetically).
I say aesthetically as it runs sweet enough and I'm getting good voltages out of the stator, RR and at the battery. I would like to tidy up the wiring, insulate it properly (PO went a bit mad with a roll of yellow tape!) and relocate some components.

I'm pretty sure the board under the tank and the metal box over the shock are bodged mods and i would like to restore the electrics back to standard (or as near as possible). The battery tray has been chopped off along with the pillion pegs.

Any information, pictures or suggestions on stock electrical layouts would be most appreciated.

I've also read that the 40mm carbs will be too big for the bike but I can't afford new carbs so looking into extending air filters/trumpets etc. Suggestions?

I will be selling all of the stock parts from my 17" conversion in the near future so get in touch if they can be of use to you.

Hopefully I'll have her on the road pretty soon, then maybe look about putting her on the track...

I will keep updating with pictures and progress over the next few weeks.

Cheers, Rob.
1989 Ducati Sport 750
1995 Ducati Monster 600
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ducinthebay
paso grand pooh-bah
Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Re: 1989 750 Sport Project - Any Suggestions?

Post by ducinthebay »

Welcome to the site. The fact that you are excited about buying an obscure Ducati in that condition proves that you belong here. You will find many similarly afflicted here.

Indeed, the electrics have been buggered with. the battery used to be by the headset, and the rest of that wiring used to be under the seat. The coils used to be in the breeze under the battery. The old battery tray is now missing.

You might be better off getting an entire harness from a Monster or SS and installing it, as most of the electrics were under the tank for those bikes, and may fit better that what you have now. Make sure the housing for regulator is grounded.

That is a very interesting tail section. I'm not sure what that is, but maybe its just an F1 copy. I see the P.O. also liked gold spray paint as much as he liked yellow tape.

If you are diving into it, I would recommend getting a complete front end from a Monster or SS and put it on. Making bits to fit new calipers, and also the speedo bit is some fiddly work, and the newer forks are, well, newer.

The 40mm carbs may be a bit much for the engine, but I'm sure you have read that already.

When the fuel pump was yanked from the tank, did he also cut out the steel tubing in the tank?

The rear passenger peg holders and muffler mounts have been cut off the frame I see. I can't see any other mods beside the battery tray.

Well, with old bikes like this, there is always the debate whether to modify or keep stock. I think you already know which direction this one is going. No sense in looking back on this bike. Modify at full speed.


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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paso750
paso grand pooh-bah
Posts: 5558
Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: 1989 750 Sport Project - Any Suggestions?

Post by paso750 »

The fact that you are excited about buying an obscure Ducati in that condition proves that you belong here.


That`s so true :lol: :thumbup:
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Maico88
Posts: 73
Joined: Sun Oct 05, 2008 1:32 am
model: 750 Sport
year: 1990
Location: Georgia, USA

Re: 1989 750 Sport Project - Any Suggestions?

Post by Maico88 »

Welcome. I love my 750 sport. Mine is a 1990 and I am running 36mm Delortos. The bike starts very quickly hot or cold and does not have any flat spots or surging. If it makes you feel any better, if the previous owner has removed the metal lines in the tank all is not lost. I have been running my Sport without a fuel pump for some time now. I also removed the steel lines from the tank. If the lines are not removed the usable amount of fuel in the tank is very small. A word of caution, the lines are much easier to remove than to put back.
Mc tool
paso grand pooh-bah
Posts: 1875
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Newzealand

Re: 1989 750 Sport Project - Any Suggestions?

Post by Mc tool »

paso750 wrote:
The fact that you are excited about buying an obscure Ducati in that condition proves that you belong here.


That`s so true :lol: :thumbup:
Yes ! I am surprized that this site doesn't have a list of recommended therapists ( other than its own members ) :lol: :lol:
I wish I was young again............Id be heaps smarter than last time
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ducinthebay
paso grand pooh-bah
Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Re: 1989 750 Sport Project - Any Suggestions?

Post by ducinthebay »

It looks as though your bike is an early production version. Your frame does not have the diagonal brace tube to the head set. I would assume that you don't have the 3mm spacers on the right hand side between the motor and frame.

Here is some fuel for thought. A TT2 racer ---
http://www.bikeexif.com/ducati-racing

Or this Flat Red--
http://www.bikeexif.com/jvb-moto-ducati-flat-red


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.
bobbyb13
Posts: 5
Joined: Sun Jul 17, 2011 4:11 pm
model: 750 Sport
year: 1989
Location: West Midlands, UK

Re: 1989 750 Sport Project - Any Suggestions?

Post by bobbyb13 »

Hello and many thanks for the replies. Having spent a bit of time researching and thinking I now have more of a direction to head in.

I intend to move the battery along with starter solenoid, fuse block and flasher relay as far back under the seat as possible (on the remaining tray section). Then RR and ignition system mounted on a plate where battery tray used to be. I can't afford a new harness so will re-wire it all myself.

That tail section is an F1 copy, again, it is a bit of a bodge job but it will do for now.

I'm going to stick with the standard forks and make up caliper adapters for now, I do have a set of M1Rs that I may put on in future. What do you mean by the "speedo being fiddly work"? Is it not just a case of fitting a speedo drive from a monster or ss and playing about with spacers? Does anyone have experience of this?

The fuel lines are still in the tank, I may look about finding a replacement pump or just remove the lines. An F1/TT tank would be nice to put on the sport but don't think it will fit due to the forward facing carb on the rear cylinder?

I DO have the 3mm spacers on the right hand side, not sure what diagonal brace tube you are referring to ducinthebay?

I love the look of the TT2 in the link, perhaps over the winter I can try and reproduce something similar...

Cheers, Rob.
1989 Ducati Sport 750
1995 Ducati Monster 600
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ducinthebay
paso grand pooh-bah
Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Re: 1989 750 Sport Project - Any Suggestions?

Post by ducinthebay »

The speedo drive that fits the 17" wheels is wider than the speedo drive for the 16" wheels. It will all mount up, but your wheel will be off center in your forks. On the 907, the left fork leg is machined more than the right leg (I forgot exactly how much) on the inside of the fork leg where the speed drive touches off. Since everything is pulled to the left leg, that's what centers the wheel in the forks. It will also play with your caliper/rotor alignment.

Milling the fork leg to be dead flat to the threaded bore is not a simple task. The mill setup will take quite some time, and the cut on the fork leg will take 30 seconds. Find an experienced machinist. If that face is not cut square, you will have some binding in the front end and short bearing life.

Wire harnesses are usually fairly cheap on e-bay. Not much demand for them. I have often seen them for $20.

The fuel pump assembly is same as the SS series, and will pop right in. Again, e-bay is your friend, or a local wrecker. You might find the guts in a damaged tank.
The seal around the fuel sensor often fails if overtightened, and will leak. If you pull it off, inspect the green o-ring and don't over tighten.

The diagonal brace is 6mm or so piece of tubing that runs up to the head tube in the front. I'll see if I can take a picture when I get home. I just assumed that the brace and the 3mm spacers were implemented together, but now I guess there are 3 versions of the Sport frame. Go figure.

The M1R fork will work lovely on the Sport. I have it on both of my Sports.

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.
bobbyb13
Posts: 5
Joined: Sun Jul 17, 2011 4:11 pm
model: 750 Sport
year: 1989
Location: West Midlands, UK

Re: 1989 750 Sport Project - Any Suggestions?

Post by bobbyb13 »

Many thanks ducinthebay, It seems as though you are highlighting problems before I encounter them, it's almost like being able to see into the future ;)

I do know a good machinist who is going to make caliper adapters, wheel spacers, 39T sprocket etc. I'm pretty sure he could sort the fork leg out for me. Am I right in thinking that the M1R fork leg will also need machining? If so I will just go right ahead and install that to save hassle further down the line.
I'm reluctant to fit modern USD forks due to cost and I would like to keep the bike as "period" as possible. I know it sounds a little silly after fitting 17" rims, 320mm rotors and 4-pot brembos but I consider these mods essential.

Any opinions on the original rear shock and possible improvements to it?

I will look into a wiring harness from ebay, do you think it is a simple case of plug and play or would I need to modify much?

I will have a closer look at the front end tomorrow, it's possible that in trying to create a F1 replica the PO chopped the diagonal brace off. I'm happy to have the 3mm spacers in, if I should ever blow it up then at least I have options for engine replacements...(900 :thumbup: )

Cheers again
1989 Ducati Sport 750
1995 Ducati Monster 600
User avatar
ducinthebay
paso grand pooh-bah
Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Re: 1989 750 Sport Project - Any Suggestions?

Post by ducinthebay »

I can see into your future because I have been there. Or at least where you are going. My bike was pretty rough when I got it, and I spent way too much time on it. But now its a great bike. Not one like it for miles.

Your machinist friend won't need to make any wheel spacers. The rear wheel is as simple as putting on a new 17" rear wheel, but you also need the newer rotor, caliper, and caliper mount. Fits right into your swingarm. Probably want to get a new brake hose while you have it apart.

With the 17" rear wheel, you can use all of the newer sprockets. Also cheap on e-bay. Common gearing for the Sport, and Paso is a 15/40.

The front only needs the speedo drive to match the wheel, and machining the inside of the left fork leg(besides the brake adapters of course). If you are lucky enough to have some 907 forks, then you won't need to machine them, as they came with the 17" wheel already, and you won't need the brake adapters either.

The rear shock is the same as the 900ss. the 750ss had a 1/4" (6mm) shorter shock, which will just slow down your steering, but will work. If you get an aftermarket shock, you can adjust the ride height.

If you find an early 90's wire harness, all the connectors should match you bike. Color codes didn't change much over the years.

There would be no reason for the PO cut out those diagonal braces. I would guess your bike just wasn't built with them.


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.
User avatar
ducinthebay
paso grand pooh-bah
Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Re: 1989 750 Sport Project - Any Suggestions?

Post by ducinthebay »

If you need some more fuel for the imagination, here is site to get lost in for a bit.
http://www.ducati-tt.de/index_en.htm
TT's, and F-1's
Cool stuff from the dark days of Ducati. How did they survive that era?

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.
bobbyb13
Posts: 5
Joined: Sun Jul 17, 2011 4:11 pm
model: 750 Sport
year: 1989
Location: West Midlands, UK

Re: 1989 750 Sport Project - Any Suggestions?

Post by bobbyb13 »

So, it has been about 7 months since I updated this post. Progress has been slow but I am now back on track for getting the Sport on the road by THIS summer!

Finally managed to find the money to purchase the brakes, tyres and get caliper adapters machined up etc. I now have a rolling chassis with 17" wheels, new rubber and modern brakes.

There is still loads to do before she's back on the road but it just needs time investing and not money so I should progress a lot quicker....

Image

Image

Image


I hope you are all well and enjoying your bikes, whatever state they may be in.

Cheers, Rob.
1989 Ducati Sport 750
1995 Ducati Monster 600
User avatar
ducinthebay
paso grand pooh-bah
Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Re: 1989 750 Sport Project - Any Suggestions?

Post by ducinthebay »

nice work. Looks well sorted.
My goal the year I got mine running was to ride it into the Moto GP at Laguna Seca. She was a little rough, but she was there. Looking forward to a pic of the bike at the track with lots of other Ducati's around.

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.
Mc tool
paso grand pooh-bah
Posts: 1875
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Newzealand

Re: 1989 750 Sport Project - Any Suggestions?

Post by Mc tool »

Yeah , it does look good. I passed up the option to buy a real rough on of these a while ago and I am starting to regret it .I always liked the way the bikes ( the 750sport ) looked and all the usual mods , like yours only made them better, mmmmm must keep my eye open for another :)
Well done so far
I wish I was young again............Id be heaps smarter than last time
User avatar
ducinthebay
paso grand pooh-bah
Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Re: 1989 750 Sport Project - Any Suggestions?

Post by ducinthebay »

While you have the bike apart right now, I do suggest changing the rear shock if it is still stock. A 900ss shock will fit right in, and are the same length. After 1999, the stock 900SS shock got 6mm longer, which is nice on the Sport. In general, the newer shock has much better damping, is adjustable, and has a reservoir, so in general, just a better shock than what the Sport came with 20 years ago. They are also fairly cheap on e-bay or other sources. You might find used shocks that have been revalved or rebuilt, or re-springed also. I found one that was rebuilt by a Lindermans, a local suspension shop, and had a Hyper Pro spring on it (for my weight) for only $150 (Rebuild/revalve =~$100 - 150, new Spring =~$150) the previous owner finally upgraded to an Ohlins. I know you are on a budget, but if you troll the ads, you might find a deal. The modified stock shock sold for less than many stock shocks on e-bay, and had only one other bidder. Works great.

If you lived closer, I would send you a stock '96 900ss shock I now have as a spare.

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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