Another carb swap project

[lammy1]

Hello all,

after reading through the forum I (at last) discovered what could be done about proper carburation.
So many people say bin the Weber and buy some other carbs.
So off I went, buying a Mikuni set from a 750ss.

They were not that expensive so here comes another project for me this winter.
I do have some questions.
On the carb are five tubes what are these for?
I pointed them out with a coloured arrow so we all know which tube we are talking about.
Can anybody give me some hints please?

see pictures below

Thanks
Frank

[motiztab]

Frank,
The green and red hose's are breathers, each has a non return valve. Its the unit just below your green arrow. These need to be route to a catch tank.
Yellow is fuel inlet.
Blue is fuel outlet

You coulld do with reading the conversion write up by Gerhard Hippe, worth reading
I do not have a link but I am sure he would not mind me sending you a word doc copy.

http://forums.ducatipaso.org/viewtopic. ... pic&t=1453

this has a link to some images of my bike which got half way into the conversion but for other reasons i stop. I now regret it as i sold the carbs which looked like new!

[lammy1]

Why has the green and red hose to go to a catchtank?
Can't they just go to the ground?
The catchtank will become full off fuel or am I missing something?

Fuel outlet is the return to the fueltank?

Sorry for the "stupid" questions but I want to be sure.

thanks
Frank

[paso750]

Frank,

you will find most info here:

http://forums.ducatipaso.org/viewtopic. ... c&start=15

and you will find some more info in the download section, "technical ocuments" page 2.

Catchtanks should be used for the breather lines. Just leading these lines downwards could cause underpressure in the lines when driving which may influence carburation. The catchtanks do nothing else than keep the line`s end in a windfree environment.
Basically the same for the fuel catch tank. These tanks are not sealed they have some small holes in them so the fuel catchtank will not overflow. When the carb setup is right there will almost be no fuel running into the fuel catchtank.
The fuel outlet just leads to a catchtank while in the fuel IN line there`s a Y split that leads back to the tank.
At least that`s the setup on a SS and the same I used.

Gerhard

[lammy1]

Thank you all for your responses.
I now know how to connect my carbs. (I hope)

There is only one question left for me, is it possible to lead the green, red and blue hose to one catchtank?
Or is it advisable to make seperate tanks for the green and red together and one for the blue one?

greetings
Frank

[paso750]

good question. Can`t answer that one. Worth a try.
On Monster and Supersport there`re 2 catchtanks

G.

[750pheonix]

this has a link to some images of my bike which got half way into the conversion but for other reasons i stop. I now regret it as i sold the carbs which looked like new!

Well if you still regret the decision you'll get a second chance shortly as they'll be going onto Ebay. I had to sell the bike as the engine was gone... far beyond what i could afford to repair... and i don't have a garage.

Keep you eyes peeled...

[motiztab]

750pheonix

You have PM

[Finnpaso]

How important are those "non return valves" in breather lines, cause seems, that Elephant dont have such valves at all? Those hoses were routed only under/behind, (whatever) carbs with 90 degree curves, not to any tank.

Does Mikunis need fuel pump in 750 Paso? Is it so, that if tank fuel line is lower, than Mikunis, then need pump? (if no pump, then still fuel in tank, when Mikunis dont get anymore fuel with gravity feed)

[Tamburinifan]

Those hoses were routed only under/behind, (whatever) carbs with 90 degree curves, not to any tank.

No tank needed, only still air f their vaccuum functions.
Route them to a still place.

Is it so, that if tank fuel line is lower, than Mikunis, then need pump?

Yes.

[Finnpaso]

Yellow is fuel inlet.
Blue is fuel outlet

WRONGLY !!!!

Via versa:

Yellow is fuel outlet
Blue is fuel inlet

Guys, look closer Haynes SS/Monster book and there those hoses are explaned just via versa with better foto(foto nr.8.6).... I taught so also, cause fuel inlet hose was covered by textil and outlet was only fuel resistive rubber.... I trust Haynes book. :laugh:

[Rodney]

the breather hoses with the return valves need to go to a airbox with limited flow otherwise the needles wont operate properly .
ducati part no. for air box is 58510101A .
hope this helps.

[Finnpaso]

So, to WHERE put those breather pipes, if use pod filters? Someone say, that they should route ONLY to such place, where is not anykind air pressure to go in(some tank, or bottle..). I understood from that, that no need to route them to any airbox! (and can then use also pod filters)

[paso750]

here is a pic of Mikuni as they had been removed from the bike

and this is how I had put them on the bike


I guess Rodney is calling these "airboxes", so I think there`s just a misunderstanding here.

G.

[Tamburinifan]

So, to WHERE put those breather pipes, if use pod filters?

I routed them behind the airbox on my Monster. That was still enough
and worked good.

Think it`s a little misunderstanding w airbox:
The hoses shouldn`t go to the big inlet airbox but to the two small ones as in the pic:


BUT, you don`t need those grey boxes, just route them to a still place.