Carbs & intake manifold

eliatt · Post by **eliatt** » Sat Oct 06, 2007 12:16 pm

Hi all,
I just came across 1994 cagiva Elephant 900 owner that upgraded to 900ss engine.
He has carbs & intake manifold to offer. I thought it will suit my 750 Paso, but I wish to consult with you guys. what do you think? is the manifolds are direct fit? carb may or may not require re Jetting?
any thoughts are welcome!
Thanks in advance,
Eli

Post by **paso750** » Sat Oct 06, 2007 2:33 pm

Hi Eli,

carbs fit, inlet manifolds also, airbox does not. Not sure about throttle grip and cables (throttle & choke), these may be too long but not a problem. Throttle grip of a Supersport fits and I only can guess that Ducati used the same on both models.
Rejetting will be required alhough it may run like that, specially if you have an aftermarket exhaust and/or you will use sport airfilters on the carbs.

G.

Finnpaso · Post by **Finnpaso** » Sat Oct 06, 2007 7:26 pm

....something, like i have thinked.. I bought Mikunis from 900cc Elephant and want to adopt them to my 750 Paso this next winter. I have allredy Mikunis, Elephant airbox, inlet manifolds. Seller told, that original Weber throttle cable will fit perfectly(buy i havent tried yet). If someone have details, how to adopt Elephant airbox to Paso 750, let me know... courious, but seems, that easier job, than make airbox from Paso original airbox... Elephants airbox looks smaler and easy to find normal filter to it... "only taught still"...

Gwenadu · Post by **Gwenadu** » Sat Oct 06, 2007 9:14 pm

why do you always think that the airbox is so important??? Mine have cylindric KN filters and runs well... Just too noisy for long travel!
Alain.

eliatt · Post by **eliatt** » Sat Oct 06, 2007 9:46 pm

Thanks all,
I guess 750ss carbs/intake manifolds/airbox will suit better, am I right? I`ve got that option too. sould I take it?
Thanks again,
Eli

Post by **paso750** » Sun Oct 07, 2007 9:32 am

the carbs are the same, only difference between 750 and 900 models is their jetting.
Inlet manifolds look the same but they are not. If you use 900cc inlet manifolds on a 750 the carb will stand slightely twisted which has no impact at all if you use open filters or build something by your own.
I don`t recall having ever seen an Elephant airbox but I doubt it will fit.

eliatt · Post by **eliatt** » Sun Oct 07, 2007 11:27 am

Thanks, I think I`ll go on the 750ss option, since jetting probably will be the same - in good proximity, and I may be able to use the air box ( filter seams to have same dimensions).
Did anyone tried it & can share his views?

Post by **jcslocum** » Sun Oct 07, 2007 1:12 pm

Gwenadu wrote:why do you always think that the airbox is so important??? Mine have cylindric KN filters and runs well... Just too noisy for long travel!
Alain.

Some airbox info. This write up relates to the 748-998 type bikes but the info is relevant.

http://www.desmoducati.org/airfilter.html

ducinthebay · Post by **ducinthebay** » Fri Oct 12, 2007 9:55 pm

Once again, John has spoken wisdom beyond his years, no matter how old he is.

The intake system is indeed a complex issue once you start talking about negative waves, positive waves, resonance, flow, velocity, and a host of other issues. Here's another good article that will add some depth to the issue;
http://www.grapeaperacing.com/GrapeApeR ... ystems.pdf

While you can get a engine to run, and run fine, with out some sort of plenum, you can get the same engine and carburetor to run much better with a proper plenum/intake track. When in doubt, add more intake length. An air filter attached directly to a carb is acceptable to get it running, but should never be considered as the ideal situation.

Again, all of this is based on street riding and using all of the RPMs in the range. Even if you only live in the high RPM range, as a race engine does, you should tune your intake track for the flow and resonance that you expect to see.

It hasn't taken me much reading to know that I have no way of designing the ideal intake system. But likewise, I can see that a stock airbox is probably the best option, and if I don't have that option, since I have Dellorto's, adding some length of runner between the carb and aircleaner will help and not hinder.

Cheers,

Phil

Post by **jcslocum** » Sun Oct 14, 2007 12:06 am

ducinthebay wrote:Once again, John has spoken wisdom beyond his years, no matter how old he is.

Jon is plenty old. 50 this year and still feeling like a 16yo Hooligan.