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Desperate for Carb help/replacement in Colorado
Posted: Sat Sep 18, 2010 9:19 pm
by docbob
The Weber carb on my 88 Paso is a nightmare. The bike hadn't run for a few years and things got gummed up, so a local Ducati performance shop found some parts somewhere and rebuilt it. The bike runs, but anything 0-1/3 throttle was a joke. The shop confessed that they didn't know what to do so I took it to a Ducati dealer in Loveland, but they only made it worse. None of the other Ducati service departments in the Denver Metro area would touch it. Does anyone know of anyone in this area who could tackle this project, or where (anywhere) I could get an intelligent rebuild job on the Weber, or probably better yet, find a complete Mikuni replacement setup? Otherwise, the bike is in great shape so I hate to have it sitting around not running.
Re: Desperate for Carb help/replacement in Colorado
Posted: Sun Sep 19, 2010 12:57 am
by angelix
docbob wrote:The Weber carb on my 88 Paso is a nightmare. The bike hadn't run for a few years and things got gummed up, so a local Ducati performance shop found some parts somewhere and rebuilt it. The bike runs, but anything 0-1/3 throttle was a joke. The shop confessed that they didn't know what to do so I took it to a Ducati dealer in Loveland, but they only made it worse. None of the other Ducati service departments in the Denver Metro area would touch it. Does anyone know of anyone in this area who could tackle this project, or where (anywhere) I could get an intelligent rebuild job on the Weber, or probably better yet, find a complete Mikuni replacement setup? Otherwise, the bike is in great shape so I hate to have it sitting around not running.
I would forget the Weber (it is hopless!!) and look for a Mikuni set from an SS750/900 or a M750-900; The 600 could work but will need rejetting, so better start with the correct set up.
it will take 2 hs to make the transplant and you will need:
- set of cables and Throttle
- set of inlet headers & gaskets
- set of Mikuni
- set of single K&N filters (to start, later you could transplant a whole airbox)
mikunis and headers could be purchased on Ebay, just keep an eye and they will pop up. gaskets filters, cables and throttle will have to be sourced through a shop.
When I did my P750 I went all the way and made also a complete airbox transplant and took me 4-5hs and 120$ (sourced most parts on ebay)
IF you really want to get the weber working, FORGET the DUcati store and take it to a weber specialist. Those carbs were very popular on European sport cars of the 70s and 80, therefore any CARBURATOR SPECIALIST will have the overhal kits and the necessary equipment fo reconditon and rebuild your weber.
Once it is refurbished then you can fit it on the bike and do the small adjustments.
Re: Desperate for Carb help/replacement in Colorado
Posted: Sun Sep 19, 2010 1:20 am
by higgy
Re: Desperate for Carb help/replacement in Colorado
Posted: Sun Sep 19, 2010 2:19 am
by angelix
Weber are fitted on most classic Alfas, Fiats, Ferraris etc of the 60s-70s and 80s
I am 100% that in the US there are carb specialists cabable of overhauling them , in fact it is just a matter of spending 15 seconds on google to find one like
http://www.webercarburetors.com ; they are not in Colorado, but shipping a small box from NY shouldn't be a big issue.
alternatively, stick weber 44DCNF on EBAY and there are AT LEAST 2 vendors showing the kits (they ship worldwide)
Having said that the Weber was replaced by the Mikunis because it was crap very unreliable and un-easy to maintain.
Re: Desperate for Carb help/replacement in Colorado
Posted: Sun Sep 19, 2010 4:50 am
by higgy
Weber are fitted on most classic Alfas, Fiats, Ferraris etc of the 60s-70s and 80s
I am 100% that in the US there are carb specialists cabable of overhauling them , in fact it is just a matter of spending 15 seconds on google to find one like
http://www.webercarburetors.com ; they are not in Colorado, but shipping a small box from NY shouldn't be a big issue.
alternatively, stick weber 44DCNF on EBAY and there are AT LEAST 2 vendors showing the kits (they ship worldwide)
Having said that the Weber was replaced by the Mikunis because it was crap very unreliable and un-easy to maintain.
Sorry guys,one more Weber rant
Lets not forget Maserati, Porcshe, Lamborghini and VW. But here we are talking about the DCNF series. The DCNF series is not your run of the mill Weber and found its way onto precious few vehicles to begin with and most of them went on club racers. There is only one outfit in the US or the rest of the world for that matter that still carries the full line for the DCNF (most days) and that would be Pierce Manifolds in California. Not in Italy or Spain where the Weber was originally produced. Yes there are a few other venders that carry a basic line of jets and gasket kits. I have spent the last two years searching and providing parts for the DCNF series I know exactly what I am talking about. The Weber in fact was the pinnacle of high performance purpose built carbs and far from what you describe as crap and high maintenance. It was and is still one of the simplest and easily configurable carbs ever made anywhere. Mikuni back in the 70's became widely known because of their ability to provide Weber knockoffs at half the price and required their distributors to carry a complete line of parts. All that being said, The DCNF is not for everyone. If you are paying someone,assuming you can find someone to do the job( good luck

) it will cost you a not small fortune to get it setup properly and there are precious few that will even consider or are capable of taking on such a task. It is not a difficult job at all for someone with a good idea of how a carb works. But these days it is very time intensive as the parts take time to get and can be hard to find at times. If on the other hand you have the time and are willing to learn the skills you can do the job yourself for 100 to 200 bucks, less if you have the right calibration or are close to begin with( few do as fuel has changed much over the last 20 years). Opinions on this subject are of little value to me, I dont get mine from a magazine. I deal in facts only.
The plain fact is there is no more satisfying sound on the planet than a properly set up Weber on a Paso, but there are few that ever knock on this door, those that do never look back.

and have very large smiles on their faces every time they hear that desmo come to life

jm2c Ain't no Mikuni gonna do the same
rant over......for now

Re: Desperate for Carb help/replacement in Colorado
Posted: Sun Sep 19, 2010 10:31 am
by angelix
Rant...
of course everyone is entitled to his opinions.
the DCNF series is very well known to me and I always got them right by simply taking them to a serious weber specialist (2 generations of experience) in my home town in Italy;
My own P750 had a complete rebuild and for a while it was OK, unfortunately as soon as it started to be ridden on twisty roads and mountain passes, well.. things changed for the worse.
The reason is simple, the Weber cannot work properly with the dynamics involved in a motorcycle, that is it; Ducati got it wrong, tried to fix it, couldnt and went to use a more suitable set up.
And in MY personal situation, the Mikuni set up was a blessing and finally I started to enjoy riding the bike as Tamburini intended.
Re: Desperate for Carb help/replacement in Colorado
Posted: Sun Sep 19, 2010 11:15 am
by higgy
The reason is simple, the Weber cannot work properly with the dynamics involved in a motorcycle
Bullshit,, more FUD
The only issue with the DCNF is it has no power valve. Which is why it is not for everyone,
Has nothing at all to do with the motorcycle and it's "dynamics". It is strictly an issue of topography, large changes in elevation or big changes in weather it was never designed to deal with. It never had much success at Pikes Peak

It did however reign supreme at the track for 25 years The DCNF came about to provide a highly tunable instrument for maximum performance. It was never meant for your family sedan. Ducati did not get it wrong, they simply failed to compromise. There is however a very simple solution which works fairly well for your average ride. Yes if you spend most of your time riding in the mountains the mikuni is a better choice, no argument there. It is however a compromise. It will also cost you more than 120.00 unless you are lucky enough to run across the complete setup from someone who went the full route to FCR's. FCR's remain the only comparable option to the Weber performance wise. FCR's will set you back any where from 800 to 1000usd.
In your country, Alfa1750 carries a larger than most selection of jets for half the price of everyone else. She does not however carry the full line for the DCNF
Re: Desperate for Carb help/replacement in Colorado
Posted: Sun Sep 19, 2010 2:20 pm
by angelix
higgy wrote:
Bullshit,, more FUD.....
as I said is a mattter of opinions.
Ducati used the Weber and the Digiplex two devices SPECIFICLY conceived for the car industry and they got it wrong from the begining; both were perfect on the cars, but on the Paso it simply did not work.
I remember every single Time I started my bike there was an issue, partially resolved when I ditched the digiplex and finally when I replaced the Weber.
the proof is in the several tens of thousands of bikes carrying the Mikunis (kokusans), that came after the Paso Series.
It is not only a matter of performance , Paso and Sport were NOT designed to be race Bikes, but Gran Turismo and Turismo Sport bikes, machines intended to be used on the road, any road in any wheather.
It is clear you love your webers, and you can compromise, spend hours trying and eventually fixing the issues, but most of the users want JUST to jump on their bikes and go withouh having to compromise on the riding experience or spend their time working around their bikes.
Re: Desperate for Carb help/replacement in Colorado
Posted: Sun Sep 19, 2010 2:36 pm
by higgy
Re: Desperate for Carb help/replacement in Colorado
Posted: Sun Sep 19, 2010 3:40 pm
by englishstiv
Re: Desperate for Carb help/replacement in Colorado
Posted: Sun Sep 19, 2010 5:11 pm
by paso750
As angelix stated if you get Mikunis it doesn`t matter if they are from a 600/750 or 900. Also the Yamaha TDM used them. You´ll have to change the jetting accordingly. Regarding the inlet manifolds though you should get some from a 750 engine as the ones from a 900 are slightly longer.
Higgy, just wondering. Have you ever had or ridden a Paso with Mikunis ?
I won`t say anything positive or negative about the Weber as I didn`t really give it a chance ditching it only little time after getting my bike. But no matter what you can get out of the Weber swapping it for me personally was like the doing the coils wiring mod. After doing it I never thought of this topic again. This and some other mods really made my Paso a low maintainance bike. (compared to some other old Ducs out there that is, obvioulsy not compared to a XT600 or so)
If I ever get another Paso I may give it a try.
G.
PS: STFU doesn`t really belong here I think.
Re: Desperate for Carb help/replacement in Colorado
Posted: Sun Sep 19, 2010 8:08 pm
by higgy
Re: Desperate for Carb help/replacement in Colorado
Posted: Sun Sep 19, 2010 9:43 pm
by angelix
We are still Off topic, but since you asked politely, I will reply:
I have (had) a Paso simply because I like the history behind it; it is the very first bike of the Tamburini era, it has a terrific design for that time and an engine close to perfection (the 750 with big valve heads)
I owned and completely restored two P750; one was sold completely original, the other with a Mikuni set and since I had both in my garage I actually had the chance of comparing them side by side.
By The way, I think Tamburini hated the idea of using the Weber set up (he is a Purist and a perfectionist), unfortunately those were the company guidelines and most probably he couldn't refuse (or maybe there was no alternative available on the short term) and with the release of the SS and the Monster they finally had the chance to replace it with the less temperamental Mikuni set
I am also convinced that the idea of using the Digiplex was only because this way they could use different progressive advance maps with the intention of getting it to work ... unfortunately it did not.
I have also a 907ie (and several other bikes , all European, including a 916 and a very Special 750SS I am building); Sadly I had to make a choice (lack of space) so I decided to keep the 907ie and sell the P750s.
It took me over a year to find my 907ie as I wanted it red, one of of the first 500 ever built (#315) and with "BO" plates (BO stands for BOLOGNA).
end of the OT (maybe)
Re: Desperate for Carb help/replacement in Colorado
Posted: Mon Sep 20, 2010 3:11 am
by higgy
By The way, I think Tamburini hated the idea of using the Weber set up (he is a Purist and a perfectionist), unfortunately those were the company guidelines and most probably he couldn't refuse (or maybe there was no alternative available on the short term) and with the release of the SS and the Monster they finally had the chance to replace it with the less temperamental Mikuni set
I am also convinced that the idea of using the Digiplex was only because this way they could use different progressive advance maps with the intention of getting it to work ... unfortunately it did not.
Not even going there

More "OT" FUD only proves you can read some one elses opinion.
I will however offer up the following fact.

The only mistake Ducati made with the Weber was not taking the time to develope their own emulsion tube/auxilliary venturi combination to get the calibration correct out the door. The Weber was after all for over forty years "THE PURIST CHOICE FOR PERFECTION IN CARBURATION"
The Digiplex suffered from the same ailment as all the rest who early on went to this sort of ignition. Heat and poor electrical connections would eventually fry the output transistors. Had nothing at all to do with the
" failure of the Weber calibration in the Paso"
One more fact to offer up. There is not an ignition system on the planet that will make up for an improperly calibrated fuel system. It can however certainly enhance proper fuel management.
Both of these issues are a failure of the quality management system,not the engineering behind the designs
As to Why the Weber was ever considered I offer up the following quote from THE Defacto Weber Experts In the USA.
What makes Weber carburetors so special?
Weber carburetors have been standard equipment on the finest racing and street machinery to come out of Europe for over four decades. Maybe you've been lucky enough to get a ride in a Ferrari or a Weber carbureted 289 Cobra; if you have, chances are it's a ride that you've never forgotten! Weber-carbureted engines all have one thing in common: they assault the senses with a rush of torque that is generally unmatched among carbureted engines (and they have a sound all their own...go to a Shelby American convention on open track day and you can pick out the Weber-carbureted Cobras just by their sound; there is no mistaking it!). The world's most beautiful, exotic, and powerful engines have traditionally been fed through Weber carburetors. But why Weber?
One of the primary features of Weber carburetors is their modular design. They are produced in a wide variety of styles which incorporate different features, enabling the user to select exactly the right design and size for the intended use. You can even change Weber carburetor airflow capability to suit your needs –making Weber carburetors adaptable to more applications than any other.
Now, if you've always had trouble accepting the idea that Webers can be a terrific street carburetor, consider it this way: Weber carburetion is like an expensive musical instrument. If it is not tuned properly, that instrument will never make beautiful music -no matter what! And therein lies the secret of making Weber carburetors perform to your expectations -tuning.
And that is the reason I sold my set of Mikuni's and stuck with the Weber and did not go for a set of FCR's. Yes it took me a while to get it sorted out, mainly due to my work schedule and partly because it took awhile to find a source for the parts I wanted to try. It is also why I and Romus decided to publish our findings to the group here and why I started the webpage. There is no other choice in my opinion. But it is not just "my opinion" To me it is all about the sound. There really is no other sound like a properly tuned Weber, and only the FCR's can come close in terms of performance. Yes the mikuni would be a better overall choice if your ride takes you through elevations changes of more than 3500 feet. That is the reason CV carbs came about to begin with,but they are a compromise in performance in any other situation. In reliability they are all excellent choices. Tempermentalness is a result of improper tuning period.
One more point in fact, My weber on the 906 starts perfectly and much better than the 907. It also runs much better than the 907 at anything below 4500 rpm's and I believe after a few more minor changes to the air corrector jets and the final calibration of the accel pump it will run better than the 907 above 4500 rpm as well

Re: Desperate for Carb help/replacement in Colorado
Posted: Mon Sep 20, 2010 6:31 am
by Mc tool
[/quote]
and they got it wrong from the begining; both were perfect on the cars, but on the Paso it simply did not work.
[/quote]
Sorry Angelix , I have owned a webbered & digiplexed 906 for 6 years now and I have no idea what your talking about, mine goes fine.
Nowdays people are screwing power commanders to just about everthing new... to improve the standard performance figures......... nothin's changed