Vacuum pipes and distributor

[JohnFol]

Afternoon all, I've swapped my carb and found the replacement has 2 vacuum pipe attachments. From what I can make out the rear one (by idle solenoid) is "ported" and goes to air filter so it can operate the flap.

However another article suggests that for vacuum advance distributors (like mine), it needs connecting to a ported vacuum pipe on the carb.

So, I've connected distributor to rear pipe and that's all. Idles great but "lumpy" when accelerating.

Does anyone have this configuration? Should I block off the other pipe at front, swap to using front pipe...? Any ideas appreciated

[rossocorsa]

I'm not very good with this but on a quick look the technical books show the vacuum hose for the thermostatic intake attaching to the inlet manifold. I will try to remember to have a look for info on the other connections tomorrow

[Nigel]

John,
My car doesn't have vac advance so this is purely what
I think I would do.
I would feed the distributor vac from the front port and blank off the rear one.
I've not got a rear vac port on my carb, and I've not seen that before.
Maybe your carb is from a different engine/car?

I've also disabled the air filter hot/cold flap function, due to it being worn
and rattling at certain engine speeds. Nor do I have that brown plastic valve inside
the filter housing connected.

In other words I elected to keep things as simple as possible.

Nigel

[Ferrit]

on my car the front larger hose goes to the underside of the airfilter.  I also have no vac airfilter flappy thing.  The rear I am sure is vac adv/retard (which I also dont have)

[JohnFol]

Many thanks all. I have a few things to try and like the idea of simplifying.

It does sound like vacuum advance is a bit unusual.

[rossocorsa]

Many thanks all. I have a few things to try and like the idea of simplifying.

It does sound like vacuum advance is a bit unusual.

Vacuum advance is not fitted on 2000, it's on 1300, 1600 and VX I'm not sure about IE off the to of my head.
I believe that the feed for the advance needs to be taken from close to the throttles for best and accurate response
This might vary according to series, important to know which exact variation you have, Betas are complicated when it comes to updates etc. also North American, Swiss and Australia  market cars can differ.