Eliminating auxiliary enrichment on Zenith Carburetors

[Vintagemotion]

I decided to rebuild my 40 Zenith (70 911 T) after I took them apart and discovered that all in all they are in pretty good shape. One butterfly was stuck after previous owner left the 911 in the rain for some years without air ducts. To simplify the function I may want to eliminate the auxiliary enrichment feature. The crabs have an accelerator enrichment function like most other crabs but additional the Zeniths have this mysterious vacuum controlled enrichment contraption. www.gary.suggate.dsl.pipex.com website shows how to bypass this contraption.
Does anyone have a clear clue what the function of the auxiliary enrichment feature is and consequence of elimination?
Does anyone have experience or hints on rebuilding the Zenith Carbs?
Need a butterfly plate and one center shafts if someone has some spares.

Yes, I do know what the legend says about Webers......

[T77911S]

legend about webers?
i always thought the zeneths were better, not from experience, just what i heard. my brothers 2.4T had zeniths and my 2.2Ehad webers. for a stock T, it ran VERY good. i remember seeing several cars using zeniths at daytona in the late 80's.
nice web site
not sure why you want to remove that circuit

[neilca]

I removed my vacuum system and the solenoid valve. This is on a 2.0 race motor so I have little concern for the idle circuit.

I believe the Zeniths are a superior design over the Webers because the have the multiple accel pumps and they have a high speed enrichment valve. At high rpm's the accel pump nozzle discharges fuel into the venturi thus reducing turbulents in the flow.

Here is a picture of my engine/carbs with the stuff removed.

[T77911S]

i use the dollys too, they work nice

[BK911]

Removing the enrichment is as simple as removing the tubing, tapping and plugging all the associated ports. Not sure if this link explains, but worth reading anyway:

http://www.gary.suggate.dsl.pipex.com/new_site/zenith.htm

[doros911]

I removed the enrichment circuit too and I didn't know where to connect the vacuum advance hose so I did this. Don't know if it will work though.

[BK911]

The vacuum advance only needs to come from one port, not all of them. Any port will do. I think you are asking for vacuum leaks. I would plug all the holes but one, the closest to the dizzy.

[Steve@Rennsport]

Originally Posted by BK911

The vacuum advance only needs to come from one port, not all of them. Any port will do. I think you are asking for vacuum leaks. I would plug all the holes but one, the closest to the dizzy.

With all due respect,...that doesn't work very well due to insufficient vacuum and pulsations.

If one wishes to retain the vacuum advance for some reason, you'd need a minimum of 3 runners plumbed to a vacuum storage tank and then connected to the advance can on the distributor. All six is preferred.

[BK911]

I stand corrected.

On the 2.4s, didn't the vacuum just come off the 1 and/or 4 throttle body?

[Vintagemotion]

I'm still trying to find out:

what exactly does the auxiliary enrichment do?
what will change by not having it installed?
do I have to compensate with different jet?

Thanks