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Discussion Starter · #1 ·
The major overhaul is coming along fine. Valve clearances are done, new belts fitted, lots of small faults and damaged bits fixed and wiring loom ripped to bits and put back together with decently dimensioned wires and earths. Next thing I'm going to do do is wire in relays to the lights. This will cut the losses to them so they are brighter and have the side effect of unloading the wiring.

While the thing was coming apart I noticed that he inlet ports were the nicest I have ever seen on any production bike, looks like they have been finished with a flapper wheel. Me and a couple of mates stood admiring them and wondering if somebody has had work done on them. We already knew the EPROM wasn't standard and that the exhaust may be a bit special (you can see straight down inside it and it has an absorbtion type silencer. If it is a cored job then it is a VERY good one). A contact has suggested they may be from a 748R

Tonight I was looking over the pump and filter assembly and noticed the pressure regulator was dished in as though it had been squeezed to icrease the fuel pressure. I had a quick look at the 900SS engine I have ready to on the bench and it looks like somebody has given the pressure regulator on this a bash with a hammer and socket to do the same thing, Something I hadn't notice and probably explains the black plug this engine came with.

I am now begining to wonder if the 748 motor has been played with, possibly by somebody who new what they were doing. Now I have to make up a rig to test at what pressure the regulator opens at. This should be interesting. Interestingly all the suspension settings are absolutely standard - on a 1995 bike. It looks like nothing has ever been adjusted.

At this rate it should be ridabled around mid january. I'm looking forward to finding out what it goes like. When I rode it home it went straight into the garage. It went well enough low down but was unwilling to rev. This was probaly due to rotten fuel and a dirty air filter though.
 

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748's - I love them.

Good luck with your bike.

Look at everything and fix anything that looks goofy.

These are fantastic machines that occasionaly end up in the hands of shade tree mechanic's.

Spend lots of time with your bike and it will treat you with perfection.

In many ways I'd much rather have an older Duc than a newer one.

One thing I do not miss is the PLASTIC tank thing.

Happy Holidays
 

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Run it and go from there.

Since the plugs show signs of rich running check the eprom in the ecu for after market and the dash pot (aka fuel trip) in the ecu and make sure it's not set to rich.

I agree with you on the ports. I have a friend that ports head on BMW, Mercedes, Lincoln, Mazda, and Toyota cars for race and I took my 996 heads to him and he said the heads are so well ported that only someone that specializes in Ducati should touch them.
 

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Discussion Starter · #4 ·
Thanks Namor, I needed to hear that about the ports. My plan is to run it as is and see what happens. I think the black plugs may be more to do with rotten fuel but I'm going to stick in a new set of NGKs and see what they look like after a few hundred Km. The expensive Iridiums will go in once the mixture is in the ballpark and I'll tweak it from there.

Today I'm going to put the wiring loom back in - wish me luck!
 

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Thanks Namor, I needed to hear that about the ports. My plan is to run it as is and see what happens. I think the black plugs may be more to do with rotten fuel but I'm going to stick in a new set of NGKs and see what they look like after a few hundred Km. The expensive Iridiums will go in once the mixture is in the ballpark and I'll tweak it from there.

Today I'm going to put the wiring loom back in - wish me luck!
Take a pic down the intake and ill tell if its touched.
 

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Discussion Starter · #7 ·
OK, if this works we'll have some pics.

The first two are just for posterity, note the clutch in the second pic. Three and four are of the two sets of 'silencers' I got with the bike. Three is stamped A & B14 and four is stamped A & B20. The last one is the best one I got down the port - sorry about the quality but it was a trifle cold. The main loom is now finished and the battery box refitted. I then noticed that the wires from the stator are a thinner gauge than the wires to the regulator so that will have to be looked at. Bugger!

I've fitted LEDs to the back lights, parking light and instruments. This, along with the Xenon dip light should save around 40w. That along with the improvents I've made to the wiring should help keep the generator from self destructing. I've also started making up a new loom to take power to the main lights through relays. This should further help the wiring cope and give me better lights.

After all this is complete I then have to get the tank and filter box painted to match the Chinese plastics. A new chain and sprockets are now also on the shopping list. Any advice in that department will be greatfully received. I will NOT be using an ally sprocket.
 

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Discussion Starter · #9 ·
Thanks, it looks like I've got a reasonably untouched common-or-garden 748 biposto with some goodies. Can you say anything about the silencers? That'll give me a clue about how the mixture should be.

I've got a Corsa type clutch ready to go non with a set of Barnet plates. A Pipercross in-box filter is the only bit that could be described as 'go faster' that I'll be fitting for the moment. The master plan is to have her rideable and tidy ready for spring and then start dialing things in.
 

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Discussion Starter · #11 ·
Time for an updated.

Managed to make a jig to straighten the ding in the front wheel. Found the shock that caused the ding had been transmitted into the forks and shattered the plastic spacer at the top of the spring. Forks duely stripped, checked, cleaned and rebuilt with new spacers and Motul 10w oil.

Witing on new wheel bearings. Then I finish the front end. I've fitted new clip-ons with a 25mm rise. Spent about an hour and a half setting up the bars and levers so everything feels good and coes easily to hand. Something I'm a bit picky about.

After this is all done I'll get the paint fron the Chinese fairing matched and the tank and airfilter sides painted. I've toyed with theidea of chopping the 'sidepanels' off the airfilter box so it looks a bit like the 999 but given it up for now. It would be easier to screw the styling up than improve it!

I look foer a new pressure regulator as the one fitted may have been 'adjusted' with a hammer to increase the fuel pressure. I came across these: Valves, Performance items in Adjustable Fuel Pressure Regulator store on eBay!

I've ordered one. will post here a pic of it fitted, assuming it does and doesn't interfere with anything. Was cheaper than a new Marelli one.I'll need to make up a rig to see what the fuel pressure is actually set at as the bike is probably set up for that.
 

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What did you use to build that wheel straightening rig? I recently noticed a couple minor deviations in my Marchesinis that don't seem to be causing any major problems, but I'd like them fixed anyhow. I feel like most of the shops I've looked into expect a destroyed wheel and charge accordingly, and I'd rather put that money into doing the valves right.
 

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Discussion Starter · #13 ·
To get the radial bump out I jury rigged it using a 10t jack pressing of a 24mm bar through the wheel bearings to press on the inside of the rim. I had a 10mm thick by 100mm long strip of nylon plastic to spread the load on the rim and try not to damage the paint. Not 100% successful there though. To getthe sideways bump out the rim I had a 20t hydraulic press handy.
 

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Discussion Starter · #14 ·
Over haul over, 748 not sad anymore. Anybody got any spare +degrees centigrade they can send this way?
 

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Discussion Starter · #15 ·
Yup! this little baby is lots of fun and I have to be careful or I could get in LOTS of trouble - speeding fines are expensive here. The bike is behaving very well even though it isn't proberly set up yet - Gunsons gas analyser will be collected from the post office tomorrow to fix that. I have only one real worry over the bike. It is mechanically noisyer that my 900SS. Mostly in the mid range at cruise. Idle sound normal for a Ducati and full thrash everything sounds harmonious. Anybody any advice? She has 71000km on the clock so is getting a bit long in the tooth but not excessive.

This brings me on to the next little quandry. With a view to a future rebuild I've been keeping an eye on the local second hand market and picked up an ST4 motor. My thought was to just swap the heads but there is also the alternative of sticking the crank and barrels on should a full rebuild be neccesary. I know I can't just drop the engine in as the swingingarm mounts are different. Time and circumstances will dictate which way I go, oh and one other small detail. I have to contact the Ducati main dealer here in Norway just to make sure this isn't the first imported to Norway.

I remember reading a bit about the 748R that said it had a different cylinder head. Could this be the same type as the ST4? If so then a cam swap would be out of the question.
 

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It is mechanically noisyer that my 900SS. Mostly in the mid range at cruise. Idle sound normal for a Ducati and full thrash everything sounds harmonious. Anybody any advice?
My 916 is noisier than my M900, the clutch rattles more but it is also just noisier mechanically - like a metal-to-metal noise, so I would say this is normal.
 

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Discussion Starter · #17 ·
Thanks, I needed to here that. Just dumped my SS at walking pace and need to patch it up. The corner at the end of the street is blind and the paperboy was on the wrong side of the road when I came round the corner, saw him and grabbed a hand full of front brake. Thats the third time in two years I've done that. If the old lady on the corner doesn't get the hedge trimmed by next week I'll do it myself! I'll have a'quiet word' with the paper boy tomorrow morning too!

Anybody care to recommend a good book that explains how the different Desmoquattros are related to each other? I need to figur out the best combination of the bits I've got. It would appear that the 748 gearbox, primary drive and crankcases together with the ST4 crank, top end and 3 phase genny would be the best combination. The fairing 'V' might need a bit of work to fit the ST4 top.
 

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Discussion Starter · #18 ·
Finally got round to setting up the TPS - perfect. Then I looks at the butterfly synchronisation - miles out! Now it is mechanically quieter but different from the SS. It isn't really any smoother but the power is more linier. Looking forward to finding time to giving it a good thrashing! The next step is to set up the mixture and to do this properly I'll have to get the plugs on the exhaust pipes out, that WILL be fun!

One thing I noticed on the ST4 motor is that it has the oil cooler. I'm wondering if it is worth fitting on the 748 considering I live in a temperate climate (although you wouldn't think it this years). Anybody out there done it?
 
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