I have fitted a Dellorto FZD 30.24 on a 650cc engine. I need to find a way of connecting the accelerator and choke cables to it.

How is it normally done? Does a mounting frame exist for this?

Many thanks...

stjob001 said:

I have fitted a Dellorto FZD 30.24 on a 650cc engine. I need to find a way of connecting the accelerator and choke cables to it.

How is it normally done? Does a mounting frame exist for this?

Many thanks...

Click to expand...

Interestingly I was thinking/looking at this recently...
Obviously not for me being the"original Protototypi guy"

I was looking at Mini SU carbs,,,
and in particular the plate that is sandwiched between the carb and the manifold that holds the throttle cable....
(yes it would not line up but the principal)


With a cleaner looking engine either using the 126 Square head "Snail" fan housing or the alloy top for the std housing... I do not see why a simple direct throttle cable mechanism cannot be used rather than a having linkages and cranks etc etc.....

Yes it may take some experimenting with the length of the actuating arm on the carb to match the movement of the throttle pedal...
but it would be a much simpler and straightforward set up...

1 very neat way that I have seen a throttle link done for the FZD is to obtain an old/2nd hand normal, steel top fan cover (the type you have replaced with an aluminium one) and very carefully remove the throttle yoke pivot from the steel cover, match it up to the aluminium cover and mark where it needs to go. With a power-file (or similar) remove the ridges where the mount needs to be, and then bolt the pivot to the aluminium cover. By doing it this way, you can use the original throttle cable. If you then get the correct length, adjustable throttle rod (and balls) from "Burlen Fuels" you will have a good looking throttle link, to match the rest of your engine. "Burlen Fuels" are THE SU carb people (the throttle link is a SU part) and you can get the rods in a selection of lengths. The beauty of using the SU throttle rods is that one end of the rod is R/H thread and the other end is L/H thread, (as are the pivot balls) so you can very finely adjust the rod without having to take it off (it comes with the appropriate lock nuts).
As for the choke, the FZD has an accelerator pump, and in the 5+ years that I have had a FZD (32/28 on my engine) I have never had the choke connected, or needed it. When cold starting I give the throttle 2 or 3 slow depressions (depending how cold it is up here in North Wales), count 5 and then crank the engine. Doing it this way allows the fuel to start vapourising---petrol vapour fires up a lot better than wet petrol. If you really do want to connect up the choke, you have to either get an extended choke cable---a Giardi choke cable MIGHT do the job---the Giardi is about 4 inches longer. If that doesn't work, you will have to obtain a 'cable extender' and fit that into the system just before the carb.

Get rid of that dangerous plastic filter before you think of running the engine. It would be a shame to see a nice engine go up in flames.

To back-up David's advice (removing the plastic filter) the 500/126 engine does not need a 4th filter. There is 1 in the tank unit +1 in the fuel pump + 1 in the top of the carb (little disc in the case of the FZD)---in the basic 500 carb, the IMB there is a little tube filter in the top of the carb. Too many filter can actually restrict the fuel flow.

Hi.

I have had the same issue to solve on mine.
As stated above, I have also never used the choke so didn't even try to sort that.

I got my old Italian engineer friend to machine me 2 'pins', one to attach the spring to, and one to mount the original pivot to.
After much measuring, he then machined out the top of the housing to accept the 2 pins positioned so as to allow the correct accelerator movement.

I hope the attached pictures show clearly enough how it was done.

Any clarity needed, please feel free to ask.

Regards
Steve

You're perfectly correct. I didn't realise that this is a massively dangerous move. Many thanks for pointing it out....

Agreed. Many thanks...

Excellent advice. Thank you...

Many thanks for these photos. I have the original pivot and mounting it directly atop the aluminium cover makes sense. Do excuse my ignorance but where can I get the (black) coupling between the carb throttle lever and the pivot shown in the photo?

If you look at my earlier comments on this thread, you will note that I have suggested that you go to "BURLEN SERVICES". These people are THE SU carb people theses days (they own the name, the production facilities) and stock a massive amount of spare parts. Go onto their web site, and then 'SU catalogue'
--look for 'ball joints'--you will require 2 x AUE1001 (£3.40p each inc). Then go onto 'Throttle connecting rods'---these come in different lengths, so work out which one you need before ordering (the threaded sections can be cut to give a sort of 'mid-length'). I would suspect that the 5inch rod would be about right--part number AUE1005 (£28.80p inc). The quality is first class, and they are still operating their 'mail-order' facility.

stjob001 said:

Many thanks for these photos. I have the original pivot and mounting it directly atop the aluminium cover makes sense. Do excuse my ignorance but where can I get the (black) coupling between the carb throttle lever and the pivot shown in the photo?

Click to expand...

As 'the hobbler' says in his message, you need two of those 'ball joints'.
I connected mine with a piece of 5mm threaded rod covered in black electrical shrink wrap - the stuff that shrinks when you apply heat.
The rod is about 145mm long to give you a starting point.
Regards
Steve

stjob001 said:

Many thanks for these photos. I have the original pivot and mounting it directly atop the aluminium cover makes sense. Do excuse my ignorance but where can I get the (black) coupling between the carb throttle lever and the pivot shown in the photo?

Click to expand...

Hi, I use the same top cover on my fan housing and to make a linkage I have just cut an original pivot from an old top cover and bolted it onto the alloy one. A simple link arm with two ball joints fixes the carb actuation.
Ian.