DUCATI TT and F1 FORUM
 
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 Post subject: Heavy 40mm Dell'Ortos' What else will fit?
PostPosted: Mon Nov 08, 2010 5:01 am 
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Joined: Sun Nov 07, 2010 10:54 pm
Posts: 425
Location: Brisbane
Hello Graeme in Brisbane here.
I have a TT2 replica which I built. I used new type (black top) 40mm Dell'Orto carbs and had the head flowed using these carbs and manifolds.
It goes well but the throttle pull is very hard. I fitted Venhill cables in place of the Pantah cables I started with, but it's still very stiff. I've checked all the usual things like spring size and cable routing, but it's still hard and very tiring after a while.
What else will fit in the space available and be able to be adapted to the existing clamp type manifolds?

Also how do I post pictures?

Regards Graeme


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 Post subject: Re: Heavy 40mm Dell'Ortos' What else will fit?
PostPosted: Mon Nov 08, 2010 5:04 am 
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Joined: Sun Nov 07, 2010 10:54 pm
Posts: 425
Location: Brisbane
Sorry, I just found the picture posting info.
Graeme


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 Post subject: Re: Heavy 40mm Dell'Ortos' What else will fit?
PostPosted: Mon Nov 08, 2010 12:25 pm 
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Joined: Thu Oct 14, 2010 11:23 am
Posts: 1049
Hello Graeme: You say that lighter springs did not help? Have you thought about removing the pump levers? Some say you don't really need the accelerator pumps, and that they waste gas. They are another source of friction, and a cheap experiment to remove them. MikeV


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 Post subject: Re: Heavy 40mm Dell'Ortos' What else will fit?
PostPosted: Mon Nov 08, 2010 7:18 pm 
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Joined: Sun Nov 07, 2010 10:54 pm
Posts: 425
Location: Brisbane
Hello Mike,
Yes, already removed the pumps. That has made it better by getting rid of the "lump" feel as the pump lever starts to squeeze up the slide, but although smoother, it is still a very stiff throttle. (Doesn't seem to make any difference to the bikes forward progress without pumps).
I have even progressively cut the lightest springs and ended up with the slides holding up from high revs. So back to original light springs.
I can't remember my SS or Darmah with the old type 40's being that stiff with the throttle.
I was thinking of Mikuni flat slides without pumps?????
Anyone else use anything other than Dell'Orto or Mallossi ?
What else will fit?
graeme


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 Post subject: Re: Heavy 40mm Dell'Ortos' What else will fit?
PostPosted: Mon Nov 08, 2010 8:36 pm 
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Joined: Thu Oct 14, 2010 7:30 am
Posts: 129
I have Mikuni flatslides on my F1 and the throttle action is lighter than my Darmah with Dello's.The only downside is the float level on the horiz. cyl. needs to be lower than I'd like to keep the thing from drooling out the overflow at low speeds.[It is a racebike so it doesn't get much low speed use] The best but not cheap solution would be using the Keihin FCR carbs as they aren't too picky about mounting angle,have realy light action,and are very adjustable.The downside is they are about $1000 and should have a push-pull throttle so space might be a problem.


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 Post subject: Re: Heavy 40mm Dell'Ortos' What else will fit?
PostPosted: Tue Nov 09, 2010 1:02 am 
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Joined: Sun Nov 07, 2010 10:54 pm
Posts: 425
Location: Brisbane
Thanks wdietz186, what size Mikunis did you fit to your F1?
Pumps or no pumps?

Keihin FCR's are very large and I don't think they will fit. And expensive, but you get what you pay for.

graeme


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 Post subject: Re: Heavy 40mm Dell'Ortos' What else will fit?
PostPosted: Tue Nov 09, 2010 8:34 pm 
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Joined: Thu Oct 14, 2010 7:30 am
Posts: 129
Graeme, The carbs on the F1 are the TM 41 flatslides.They also are sort of large but they do fit on the F1.My recollection of a friends ex Reno Leoni TT1fitted with Malossi carbs was a very tight fit on the horiz. cyl. around the frame tubes and the carb was cranked at angle.Not having seen a TT in a long time I don't know how much difference there is compared to the F1.On my F1 I made a spacer to fit under the manifold to get float bowl clearance.With that and some reworking the manifold the carb can be fitted at a better angle so the float vents don't piddle.


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 Post subject: Re: Heavy 40mm Dell'Ortos' What else will fit?
PostPosted: Wed Nov 10, 2010 5:25 pm 
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Joined: Wed Nov 03, 2010 3:19 pm
Posts: 177
Location: Auvergne, France
hello, on my F3 with 750 motor, I intend to fit Mikuni VM carbs ( 38 or 40 mm), does somebody have used these carbs for750 ?what size

I think they are better machined than prehistoric dellortos, and cheaper, too

ciao
Philippe


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 Post subject: Re: Heavy 40mm Dell'Ortos' What else will fit?
PostPosted: Wed Nov 10, 2010 8:52 pm 
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Joined: Thu Oct 14, 2010 7:30 am
Posts: 129
Phillipe, You could use either size[38 or 41] depending on the state of tune of the engine.The 38mm would probably be a better choice for street and light track use.


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 Post subject: Re: Heavy 40mm Dell'Ortos' What else will fit?
PostPosted: Thu Nov 11, 2010 8:08 pm 
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Joined: Sun Aug 08, 2010 4:37 pm
Posts: 360
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Location: Ottawa, Ontario, The Great White North
Like Bill, I used the Mikuni TM Pro Series 41mm on my old F1 without any operating clearance issues although admittedly, the front was a bitch to remove and replace. I loved the carbs once I switched the float need jet down to a 1.8. Easy to tune and made very nice power with light throttle action (even with a 1/4 turn throttle). If you're going to be running fuel with ethanol, be aware that the float needle o-rings will only last about 18 months..

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