Tuning Dellorto FZD 32/26 Carb - Fresh Install Sound

[Bianca500]

After not having much luck getting the "Abarth" alloy rocker cover to fit alongside the IMB28 carb, instead of fettling with it to make it fit, I eventually ended up taking a punt on a Dellorto FZD 32/26 off ebay instead.

I've read a number of the threads on the FZD on the forum from over the years and there is some great content here.

I do need to sort out the throttle cable linkage, and the one I have is missing the choke aspects, however just bolting it straight on it fired up almost immediately which is great!

Based on the sound, I appreciate that it will need some adjustment. The idle is either very high or cuts out, and revving it feels flat and not progressive like I would expect. However, appreciate thoughts from your more accustomed ears before I start tinkering with it.

Is it a case of ordering a handful of different jets, and getting some time on a rolling road?

This is a 650 126p engine with "nanoplex" ignition, standard cam etc.

 

[Bianca500]

Before and after.... also need to look at rocker cover vent filter.. maybe a catch tank?

 

[Toshi 975]

Well done on finding a Dellorto FZD cab, I suspect you had to buy from Italy as they are so rare in the UK these days. Many of the carbs that do come up for sale have been used, sometimes in twin carb set ups, for applications other than little Fiats so the jets can be way out. I am sure that when Tom sees this post he will come forward with a suitable set up.

 

[the hobbler]

Well done on finding a Dellorto FZD cab, I suspect you had to buy from Italy as they are so rare in the UK these days. Many of the carbs that do come up for sale have been used, sometimes in twin carb set ups, for applications other than little Fiats so the jets can be way out. I am sure that when Tom sees this post he will come forward with a suitable set up.

Good evening---nothing like "being volunteered!". Personally, I wouldn't worry about not being able to set up the choke---my 32/28 has been onmy car for about 8 years, and have never had a problem starting it, hot or cold, even though it is "sans choke". I use the accelerator-pump as 'the choke'. Each engine will have its own characteristics, but even on a cold morning, 3 or slow pumps on the throttle will suffice. I couldn't see your throttle linkage on the pictures---is the throttle link ahead of the carb, or behind it? (rear of the car) It is best, if possible, to have the linkage at the rear of the car---it then works in fine with the original 'standard' throttle arrangement. I use a metal throttle-pivot, flattened in a vice (very technical) and then extend it, to give better leverage, and use a 'ball and socket' throttle link from "Ask the mechanic". If you drop me an e-mail ([email protected]) I will send you a picture of my throttle link, and advise you on the 'basic--try this to start with' jetting for you engine. The 32/26 is an unusual size (they are usually a 30/24 or a 32/28). Some jets are getting very difficult to obtain in the UK (as are some of the linkages and springs), but I have found a company in Italy who CAN supply most of the jets---they may not be GENIUNE Dellorto, but I have used them with absolutely no problems at all. It would be worth while if you could remove all the jets, including the emulsion-tube, and make a record of what you have---and then EVERYTIME you change a jet, you make a note of what is still in the carb, and the date of the change.
Please remove that fuel filter over the alternator---(a) it is a dangerous spot to put a potential petrol-leak part and,(b) you don't kneed it---you have, from standard, 3 in the fuel system already---fuel-tank pick-up unit + top of fuel-pump + top of carb.
Lastly, just as a matter of nosy interest, whereabouts are you in England? I am just outside Chester.