Rebuilding my Zeniths (help needed)

[farleyd]

Yup, since i dont have webers, i have to live with my pesky Zeniths. I am about to rebuilt them. Any good advices / web site / infos / references welcome.

Also, any input on how to set-up Zeniths on a 2.2T with E cams/pistons would be more than welcome.

Thanks!

[Roland Kunz]

Hello

Just remove them and check if the throttle flap axles are not worn. If yes then you better look for some ready equiped Webers from PMO.

Rebuilding the Zeniths is possible but you need good tools or a machineshop doing it.
Then with some ultrasonic cleaning and a rebuild set you can start over and fiddle the jets out.

The Zeniths are nearly direct copys from the Webers jet a bit simpler and with not so wide spread parts.

Grüsse

[DDS]

To pick up on roland's point, if the shafts bearings/bushings are good, and they were jetted for your engine, you shouldn't need much.
I just got through rebuilding three weber 42DCNFs from a maserati merak to use (2) on my 2.0 4 cyl. I was about to spend a small fortune, and a maserati resto-guy told me to be cheap and that the only thing I'd need is gaskets and accelerator pump diaphragms, the needle valves tend to just need a cleaning. (lots of carb cleaner) He gave me the UAP/NAPA part number for the diaphragms and I got them for $9 Cdn. Maybe your is the same as webers is the same as mine? Gaskets are $2.xx each and I'll need 4.
Talk to Roger at www.Piercemanifolds.com - he does weber, maybe zenith too.
Bonne chance.
Dave

[Roland Kunz]

Hello

Rebuilding Weber or Zenith makes the same work and costs similar.

The Zeniths have some benefits over the Weber but are hard to adopt as they don´t have a wide scale on parts like the webers plus most Mechanics don´t like to work on the Zenits. The Webers are very comon and every good tuning shop covers all jets and venturys to fiddle out the best setup yet good people know where to go without fiddeling to much.

The best would be you contact a Porsche shop like andial or the aase for support and buy the minimal things and see how it work out.

Minimal things are the 6 diapragmas the upper gaskets plus the recomended emulison tube, ventury ( if needed ) and jets.

The problem with the Weber and the Zenith as well is that they have allways leaking throttles on cylinder 1 & 4 while the others are still usable. This is caused by the gaslinkage.

Both carbs have teflon bushings who can be renewed but the rebuild starts when you remove the screws from the butterfly ..... things come togehter and done right once is better then done right after several throwbacks.

Also i like PMO has they allways send direct bolt ons ready to go if you provided them technical datas plus there Carbs have much better tinware then weber had ever and some other small details are improved making working on them nicer. Yet they are not the cheapest plus not the "collectors choice".

In germany we have Victor Günther who rebuild Weber/Zenith carbs for a fixprice if the core is usable, he also has racing parts and can modify Zeniths to run with 3,0 engines. I´ll check that homepage.
Only find right now: http://www.efn.org/~msayer/weboem.html

Grüsse,
Roland

[Roland Kunz]

Hello

I forgot that your distributor also need to be adoptet as well plus check the floats and the needle valves.

Ultrasonical cleaning needs a company used to handle carburators. Some speed up by using hard solvents and your carb will make trouble later ( Acid inside ).

Grüsse,
Roland

[farleyd]

Hi Roland. First off, thanks for helping.

My mechanics tried a simple test. He blowed air into different channels - dont know which - and watch if teh air was going out from the throats. The missing cylinder #2, didnt blow air out of the throats. He suggested the fuel main circuit, feeding both idle and main jets.

Can you confirm and show me where to clean it? The Zeniths have been sitting in Kleen-flo for a long time, 4-5 days at least, three weeks ago. I guess that somethoing is clogged inside.

I have compressed-air, and ready to blow some passages. If only i knew which one.

- - -

About the distributor, its already a 911E one.

Thanks!