Although my car is running very well on the FZD that I have on it, prior to finding this carb I (and a colleague) purchased 2 'new manufacture' FZD carb (32/28s) under the impression that they were 'factory' They weren't!! as far as we can ascertain they are "Chinese" copies, pretty good ones, but nonetheless, copies. After a GREAT deal of fiddlearseing around we got them to work about 95% OK. The final (inexplicably) cure was to fit the "top cover" of an old (but genuine) FZD onto the 'Chinese' carb. Sadly, we only had 1 top, off an old carb bought 'for spares'. Does anybody out there in the Forum have a proper FZD that was 'bought for spares' and, if so, would you be prepared to sell me the 'top-cover'---it doesn't matter if it came off a 30/24 or a 32/28--the top cover is the same (Dellorto part number:---6911-54---part number 14 on the Dellorto exploded drawings). I would like to get this carb working properly, so as to (a) have a good spare and, (b) feel that I haven't wasted good money by buying it. Any help would be appreciated. :bang:

Thank you for that input Peter. I have dealt a number of times with "Eurocarb", both for Weber parts and parts for my FZDs. Sadly, whilst they show part number '6911', they list it as "no longer available"---hence my request for assistance on the Forum.:worship:

http://www.carburateurwinkel.nl/index.html

It's Dutch, but they do speak English...

Hi Tom,

I'm wondering what could possibly be different between the original and copy carb. tops?

I mean, there usually isn't much to a top cover, is there?

(I'm not familiar with the Dell'Orto FZD).

AL.

The 'top-cover' on the FZD covers the whole of the carb top, including float attachment and fuel inlet--it is quite a big casting. As to why fitting a 'pukka' top-cover' cured the poor running, we honestly have no idea, but it did! The top cover is the same on both the 30/24 and the 32/28, so PLEASE if any body out there has an "incomplete, but bought for parts" FZD, I am very interested in buying the top cover---as I mentioned before the part number is "6911-54", part number 14 on the exploded drawings.:worship::worship::bang:

I've been away from the forum for a while and missed a lot of posts including this one.

I'm heading down to the shed today and will look among the spare parts and let you know what I find. I did have a spare FZD a while ago but have given a lot of it away.

Chris

Hi Tom

I also have an FZD (32/26) which is not performing as expected. It seems to dribble to much fuel into the chamber, even after much replacing of jets etc. I wonder if this is the same problem?

Tim

Chris:---Thank you in anticipation for your help, much appreciated.:worship:-----Tim:---Under normal circumstances, fuel 'dribbling' is down to a incorrectly set float, or a damaged float (punctured and therefore absorbing fuel). There are 2 weights of float for the FZD (7.5grams and 5.5grams)---I have fitted the 5.5gram float. With the 'top-cover' held vertically, the adjustment for the float is 5-6mm between the top of the float and the gasket. Another cause can be a faulty needle-valve, which if it is not fully shutting off will allow fuel to 'dribble'. Finally, the adjustment of the accelerator pump rod might be affecting the situation. If you wish, I will e-mail you with the jets and settings that I have on my 32/28 FZD. All this is on a "pukka ex-factory" FZD that was originally 1/2 a mini-cooper set. :bang:

Tom I have sent you an email about a top cover you can have

Damian

Hi Tom,

Found this naked cover - I think I know where the other parts are too. The orientation of the fuel inlet on this one means that the fuel line will enter the carby around the back of the engine as you look at it (actually the front of the engine as it's in the car).

A one stage my FZD was leaking fuel externally. The problem was a split accelerator pump diaphragm. I must have torn it during my careful (I thought) reassembly

Let me know what you want to do.

Chris

Chris; thank you for your help in this matter, I have contacted you direct (e-mail). Thank you one and all for your input/help with this problem--it just shows how good the Forum is--fair restores one's faith in human nature :worship:

Hi Tom

Thanks, that's useful advice. I'll check what you advise. When you get a spare moment please email me those settings. No hurry.

Hope you get yours sorted.

Tim

Looking at the above pic of the carb. top, I'm still wondering what could possibly be different between original and new types to cause a problem?

Difference in drilling size/passageway from fuel inlet to float valve?
Casting flash not removed?
Position of float mounting in relation to float valve?
Restricted air intake to float chamber?
Restricted air intake to above jets when cover is in place above jets?
Can this carb be temporarily run without the jet cover fitted? How does air get to the air corrector jet/s?
(I'm only guessing as I haven't seen a pic of the underside of the top cover)

Have you informed the supplier of the new carb that there is a problem?

If you could figure out the cause of the problem, you could inform the manufacturer of the replacement carb and potentially help others avoid the problem/disappointment and frustration you've encountered.
(I'm big on helping others to avoid problems that are avoidable!).

AL.

A very sensible suggestion Al, if I could out who the buggers were who made the carb! I get the impression from talking to various people (both physically and electronically) that we are not the only ones suffering these problems with the 'Chinese' 32/28 FZDs. Some dealers who were selling them have indicated that they are "no longer available". I have noted that the 30/24s are still being listed--possibly N.O.S.

A couple of years ago I did a stripdown of the FZD.

See here for details - https://www.fiatforum.com/500-classic/423634-dellorto-32-28-fzd.html

Chris

I have managed to find a Dellorto "factory" schematic of the 32/28 FZD for the "Abarth 595ss", which includes the recommended jetting for this model of car. Being that the '595ss' was listed as producing 32bhp, it pretty well matches a tuned 652cc '126' engine. If any body would like a copy, you have only to ask.

Yes please :worship:

Chris

I will sort it out for you Chris.