Tell me about my 750 Sport, please

discussion about the 750 Sport and '89/'90 900SS, which share many mechanicals with the Paso series
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kiwifruit
Posts: 37
Joined: Thu Jul 07, 2011 8:11 pm
model: 750 Sport
year: 1988
Location: New Zealand
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Tell me about my 750 Sport, please

Post by kiwifruit »

Hi folks,

I've had a soft spot for this particular model since I was 12. I'd spend hours in Dad's garage looking at his one, starting it up for my mates after school when he wasn't there. Pretty much the coolest thing as far as I was concerned.

Now I'm all grown up I've got one of my own! Still the coolest thing ever. It lives in my bedroom :-D

Here are a few pics http://www.flickr.com/photos/63757183@N ... 025257651/

and a cold start vid http://www.youtube.com/watch?v=Vmck0SNn46k

What can you tell me about this machine? It has 40mm carbs, this is not so good for smooth running down low? Filters are too close to the carbs? Are the fuel lines routed correctly? What about that starting procedure! Classic stuff. Where does the swing arm crack? I've had a good look but not taken the wheel out yet.

Thanks in advance!
Allan.
Mc tool
paso grand pooh-bah
Posts: 1874
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Newzealand

Re: Tell me about my 750 Sport, please

Post by Mc tool »

Its kinda hard for anyone to comment on the condition/set up of your bike from a few pix, but the bits I can see look real good to me .These motors are designed to make most of their power at mid revs so they aint brilliant at low revs, and my feeling is that 40mm carb's on a stock road 750 might be getting a tad large, and that wont help low rev power either. However , it should still start and idle from cold easily. I have been watching these on trade me as I too have an unexplainable hankering for one. The last one I looked at , the swingarm was cracked in several places , mostly round the shock mount. ( it was a real shitter.... I left it where it was ). Have a search in this forum , someone is bound to have posted on this topic
If you want to "fiddle " get the relevant service info ( its all here ). Where abouts in NZ are you ?
Oh yeah ! get the blimmin cat off it :lol: :lol:
I wish I was young again............Id be heaps smarter than last time
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kiwifruit
Posts: 37
Joined: Thu Jul 07, 2011 8:11 pm
model: 750 Sport
year: 1988
Location: New Zealand
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Re: Tell me about my 750 Sport, please

Post by kiwifruit »

Thanks Mc tool. It's the one from Queenstown, http://www.trademe.co.nz/Browse/Listing ... =384985349. Advert claimed it had high comp pistons, 50mm carbs :shock: and race cams. I swapped my pop up katana for it.

I know it could run better, doesn't idle without input on the throttle. Going to take it to Ian Burke in Whakatane cos i'm not the sort that should be fiddling with bikes!

I'm in Taupo.
Mc tool
paso grand pooh-bah
Posts: 1874
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Newzealand

Re: Tell me about my 750 Sport, please

Post by Mc tool »

I was watching that one,good score! :) .
A little maintainance and light tuning isn't so hard to do, but in any event you should get a manual and have a bit of a read so that you have at least some idea of whats going on , should go alright too :thumbup:
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: Tell me about my 750 Sport, please

Post by ducinthebay »

Welcome to the site, and Yeah, I can tell you a bit about what you have, and Ill guess the rest.

Yes, 40mm Dells are a bit big for that engine, unless of course there are hi comp pistons, race cams, and head work. In that case, it will probably not idle well and will be difficult to start. On the other hand, it should be great on a track. If you want something a bit more streetable, exchange those carbs for a pair of 36's. As a matter of fact, I have a pair 36's and I'm looking for a pair of 40's for my 900 conversion.

Oh, no need for the choke when starting unless is very cold outside.(usually)

Putting some rubber elbows on the back of the carbs will get your aircleaners up into the space where the old aircleaner used to be. It will also help in idling and low rpm. I put on the these; http://shop.bevelheaven.com/detail.aspx?ID=318
Then used 2" (50mm) rubber elbows. Search the posts and you will find several reverences. or, search the internet, you will find something close by. Usually diesel shops, like this one. http://www.sdiesel.com/product/90_DEGRE ... R_ELBOW_ID


Your swingarm is stock, and someone polished it. Looks nice, and the bike sounds lovely. Cracks are usually near the welds, or by the pivot if someone tightened up the pinch bolt too much (fair warning). Wipe it down and check.

Your regulator should be mounted in front of the battery, and behind the headtube. Make sure the case is grounded!! Not quite sure what you have going on there. See if you are getting a full 14v above 2000 rpm. The one that is on there is from a 70's era Ducati. Anything from an SS or Monster will work just fine.

I read the ad copy, and they said aftermarket light weight faring parts. Never seen them available before, but they surely could use some lightening up. Stock ones are heavy. Chances are, someone made them by casting from the old ones. See if you can find who made them. That would be a great resource for this list.

The two nipples on the bottom of your tank are unused, and that is not good. One is the vent for the tank, and should have a tube connected and running under the engine in case you overfill or park a full tank in the sun. the other is a return for your fuel line. The Sport has a fuel pump, and its usually too strong for float needles, and will flood your carbs. Put a "T" or "Y" in your fuel line and feed that back up to the tank. This will keep the carbs from being overwhelmed by the pump. This will make the bike run bad at low RPM also.

The Sport can not live with out the pump, unless you modify the steel lines inside of the tank that are brazed in place. The setup in the tank is the same as the later SS series. Same pump, filter sock, filter, and mounting, and fuel level float, gas cap, etc.

Otherwise, your bike looks basically stock, and in good shape. the blinkers are aftermarket, but no surprise there as the stock ones are usually broken. You are missing the rear wheel hugger. The stock one is rather huge. I have no idea if you can modify one from an SS to fit, but that would be your best bet and you can get those for cheap.

Other than that, stroll through the posts and you will find lots of other information about this bike. This is the best location on web for this bike that I have found. Read all the FAQ other sticky notes on the top.

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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kiwifruit
Posts: 37
Joined: Thu Jul 07, 2011 8:11 pm
model: 750 Sport
year: 1988
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Re: Tell me about my 750 Sport, please

Post by kiwifruit »

What a great reply. Thank you very much for that, ducinthebay. :cool:

I will see what my mechanic says about the 40mm carbs, it does (according to the advert) have high comp pistons and race cams. Probably keep them on. I'm not using the bike as a daily rider, it will sit in my bedroom 99% of the time. Be cool to take it to the track in summer and the odd ride on the road. No further than 1000km a year i don't think.

Shall make enquires about the fairings.

I took the hugger off. Quite like it without!

I'll post progress when the the fuel lines, intake elbows and regulator are all sorted.

Thanks again for all the info!
900supersport

Re: Tell me about my 750 Sport, please

Post by 900supersport »

I was watching that one on Trademe as well, it appears to be a good buy. If you are after a workshop manual for it, they turn up on trademe occassionally.
I still have a parts manual for a 750 sport, which comes in very handy, when it comes to ordering parts, so if you come across one, it's well worth getting.
For parts, either deal thru a ducati dealer or try 'Gowanlock Ducati' in Australia, it's also worth looking on trademe.
Your bike seems to have starting issues, possibly the kill switch or its wiring is playing up or the starter solenoid is faulty.
The starter solenoid lives under the seat base about where the cat is sitting, apparently the solenoid for a mini/austin 1100 may fit.
The 750 sport I had (I sold it recently), had the regulator sitting under the seat next to the starter solenoid. It appears some had the regulator up in front of the battery, which is where the slightly later 900 supersport (1989-90) had it located.
Mc tool
paso grand pooh-bah
Posts: 1874
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
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Re: Tell me about my 750 Sport, please

Post by Mc tool »

There are a pair of 38mm mikuni flat slides on tm now (390545175 )
I wish I was young again............Id be heaps smarter than last time
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kiwifruit
Posts: 37
Joined: Thu Jul 07, 2011 8:11 pm
model: 750 Sport
year: 1988
Location: New Zealand
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Re: Tell me about my 750 Sport, please

Post by kiwifruit »

Thanks 900supersport.

I see the guy i got the bike off is now selling my old Kat (i swapped it for the 750 Sport). http://www.trademe.co.nz/Browse/Listing ... =392306896

Will be keeping the 40s on for now, Mc tool. Mainly because i can't afford to do otherwise after melting a hole through one of the pistons in my other bike this morning :!:
Mc tool
paso grand pooh-bah
Posts: 1874
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
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Re: Tell me about my 750 Sport, please

Post by Mc tool »

kiwifruit wrote: after melting a hole through one of the pistons in my other bike this morning :!:

Oh no! :mad: ......... come on then ! what happened ? :) :?: :?: :?:
I wish I was young again............Id be heaps smarter than last time
User avatar
kiwifruit
Posts: 37
Joined: Thu Jul 07, 2011 8:11 pm
model: 750 Sport
year: 1988
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Re: Tell me about my 750 Sport, please

Post by kiwifruit »

Took my '71 H1 out for a pootle, it melted a hole in at least one of the pistons.... It was going to get a rebuild at some stage but now it needs a rebuild before being riden again! Still looks great in the lounge so it is allll good :D
Mc tool
paso grand pooh-bah
Posts: 1874
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Newzealand

Re: Tell me about my 750 Sport, please

Post by Mc tool »

buggery bollocks! , looks good tho :)
I wish I was young again............Id be heaps smarter than last time
User avatar
kiwifruit
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model: 750 Sport
year: 1988
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Re: Tell me about my 750 Sport, please

Post by kiwifruit »

It seems i've caught some sort of bug after riding my mate's Guzzis (1100 Sport and Daytona 1000 RS) around the last few weeks.
Symptoms include:
- Moving my 750 Sport out of the bedroom.
- Ordering the closest set of matching tyres, suitable for the weight of the bike.*
- Removing the forks and shock and sending them to be freshened up (modern 20mm pistons with modulating shim stacks in the front, rear tba)
- Sorting longer air intakes, fuel line routing and electrical testing.

I'm thinking of removing the swingarm and giving to a friend of mine, an aluminium welder, to brace. Has anyone any experience with doing this?

*Tyres are lasertecs. 120/80-16 and 150/80-16. Front is fitted, no worries. Will have to raise the guard a little. Rear is on back order, eta 3 weeks.
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Mustang505
Posts: 134
Joined: Wed Jan 28, 2009 9:27 pm
model: 750 Sport
year: 1988
Location: Auckland, New Zealand

Re: Tell me about my 750 Sport, please

Post by Mustang505 »

Hey Kiwifruit
tell me more about the forks - modern 20mm pistons with modulating shim stacks in the front? who is doing that? where can you buy the parts?
Also i have a set of 38mm Mikunis spare - the type that is fitted to 750ss from 91 onwards - if you are interested in a swop for the 40mm you have fitted.

cheers
Cheers
Clive
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kiwifruit
Posts: 37
Joined: Thu Jul 07, 2011 8:11 pm
model: 750 Sport
year: 1988
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Re: Tell me about my 750 Sport, please

Post by kiwifruit »

Crown Kiwi Technical is doing the suspension. Boxed up the forks and shock today, will be with him tomorrow. Fork internals will be either racetech or ohlins. Not sure what we're doing with the back yet, a rebuild at the very least.... maybe a fancy new ohlins unit!? I'll post here when i know exactly what's happening. All I know at this stage is it's going to be lots better than it is now!

CKT know their suspension. I had them do my 04 zx10r a few years ago. The improvement was impossible to get across with words. Robert Taylor is very good to deal with. Really looking forward to the 750!

http://kiwirider.co.nz/ckt/

I'll think about the carbs. Once it's on the road i'll let you know. Are you wanting the 40s for your race bike?
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