Carb rebuild.

[Bambino126]

I'm re-building my carb with a kit which includes 4 o-rings. I don't know where they should go, they're all different sizes.
Anyone done this?
It's the standard Weber 30 DGF 3/150 from the BIS.

[dadandlad]

From memory
The large o ring fits the large flat headed screw on th right hand side of the carb
One goes on the mixture adjusting screw
One goes on the accelerator pump jet
Struggling to remember where the fourth goes

[Bambino126]

Thanks dadandlad,
I've now just fitted those ones.

Anyone know where the 4th one goes?


One more question... the book says the float level should be 10 mm. But where is that measured from?
If it's from the lid to the top of float, the needle would barely be opening.

[dadandlad]

I used this to set my float height as the same carb is fitted to the Panda 30

http://club126uk.co.uk/forum/index.php?action=dlattach;topic=5769.0;attach=4090

[Bambino126]

Very useful.
Thank you again.

[Rusty's Uncle]

I used this to set my float height as the same carb is fitted to the Panda 30

Yes the carb fitted to the Panda 30 is the Weber 30 DGF but it is different to the Bis in that it does not have the restricted venturies with two at 23mm like late Weber 30 DIC carbs.

[Gadge]

So would a panda 30 carb be more free flowing than a BIS carb?

[Bambino126]

I would doubt it to be be honest because they are both Weber 30 DGF's just with different jetting to suit each car.

Also I've noticed Axel Gerstl sell 2 different versions of the 30 DGF both shown as applicable to the 126 BIS. The 3/150 version that came as standard and a 4/100 version.

http://webshop.fiat500126.com/katalog/showarticles/150102/1/carburetor

The panda one in the diagram dadandlad put up says it is a 1/250 version, does anyone know what these numbers mean? Is it to do with jets?

[Rusty's Uncle]

So would a panda 30 carb be more free flowing than a BIS carb?

As far as I am aware it was the forum member Deyan who first highlighted the variations in the carbs and said that the Panda 30 carb was the way to go if you wanted to get more out of a Bis. It does seem to be quite logical as a known tuning mod on the 500 carbs is to have the Venturi enlarged. Also when the Fiat 500R cars were on sale at the same time as the early 126s although they shared the same engine the 500R was slowed down by having a restricted carb fitted.