Twin su carb rebuild

[Vikram]

Hi,
I'm going through the rebuild on my twin carbs.
I'm trying to remove the throttle disc from the main body, except the retaining screws are split in two. It's the same on both carbs.
How do I remove these screws?
Thanks

[Vikram]

Sorted. Was being too timid.
Sorry for spam

[John Gervais]

Maybe this .pdf document will help you -I wouldn't be tempted to re-use those split screws which hold the throttle plate to the shaft.  They're easily damaged and I wouldn't want my valve train to ingest a bit o'screw...

[94touring]

In the top drawer of the tool chest is a little red bottle of thread locker to dab on the new screw threads.  I put in the split screws and bend them like shown, then bend further till they break off.  My way of getting better airflow and ensuring they don't back out.

[Vikram]

The rebuilt kit came with new screws, so I'm not using the old ones.
I've finished the first carb, starting the second. I see it's missing the spring for the piston lifting pin. I'm hoping it's rattling around somewhere further in the carb. If not, what do?

[94touring]

What color is the other spring?  You'll need a matching pair.

[Vikram]

Um just a silver/grey

[John Gervais]

Any small spring will work for the piston lifting pin - many carbs didn't even have these pins, so you could potentially just leave the pin out of the final assembly.  Lifting the piston to check mixture strength is pretty much touch and go anyways...

Failing that, perhaps a ball-point pen spring until you can find a better alternative?

[Vikram]

I'm tempted to just leave them out.
Thinking about it, a pen spring seems perfect!

[94touring]

I was thinking about a different spring.  Internal.

[Vikram]

Is the big spring the correct part? Two are choke springs, and the large one is the throttle return?
Pictures online show the larger spring to be of the same style as the smaller ones...

[MiniDave]

When you have dual carbs you have individual throttle return springs for each carb, some people use another for the main cable. You want the carbs to be pulled shut free of the cross linkage, then the third one pulls the accelerator pedal back up.

The two smaller springs in your pic are the correct ones for the carbs, I think the big one is your clutch arm return spring

Dan was talking about the spring that goes under the dome, and I think Vikram was talking about the little springs on the lift pins...

[Vikram]

Yup, I've been looking at that picture.
I've caused confusion here, I was originally addressing piston springs, now resolved. I'm currently on the larger springs.
I've read that people are happy running just the the two choke springs?

[Vikram]

Yup, Dave that's what was was happening. My mistake I should have read your post more carefully.
Anyway, like so

[MiniDave]

Yes, then you need a third one on the acc cable hookup.....you need to back those mainjets down about 2 turns to start with, then fine tune from there.....

[94touring]

You can pop the hood on my blue mini and look at my twins for a reference too.

[Vikram]

I did. You have set of three matched pairs as you should.
I have two similar springs, and one very random one. This seems like it was botched together from what was lying around.
I'll pick up a set of replacements