Another Zenith question

[frosty2]

Hi guys I'm still working on my zenith rebuild with one down and one to go.
Took the passenger side carb apart and noticed that my air correction jets
on this carb are all solex 195 and my other one had all solex 210.
Is this going to cause a problem with my adjustments?
Also when I removed the intake manifolds I found they all have a thin paper
gasket on the engine and then a 1/8 " approx hard spacer or gasket on top
of the thin one and then another standard thin gasket on top of that.
Is this common?

Any thoughts

P.S if your car has sat for a while you may want to do the carb rebuild it's not
that difficult and you might be surprised at whats inside.
Thanks
Mike

[1QuickS]

These affect fuel richness at high RPM (4500+ RPM) so your idle adjustments and side-to-side adjustments will not be affected. The 210s provide a leaner fuel mixture than the 195s.

[frosty2]

Thanks for the reply Paul.
I changed my idle jets from 47.5 to 55's so one likley dosen't effect
the other but would I be better off with the 195 or 210's for my air
correction jets?
Street use only no track use.
Also any idea with the multi layer of manifold gaskets, would that be
to avoid vacuum leaks?
Thanks
Mike

[1QuickS]

My guess is that someone put on lots of gaskets to be sure there was a seal or had some extra parts that fit so they were installed.

Best way to check for air correctors is to perform some full throttle runs up to redline. If midrange performance is good followed by stuttering or reluctance to rev at higher RPM then this indicates lean mixture which is corrected with smaller air jets. First step is to get three of the 195s so you have a good starting baseline.

If rebuilding OEM Zeniths for your original engine then it would be best to find what jetting was original and start there. If you are installing on a different engine (larger displacement, stronger cams, updated exhaust, etc.) then you get to have a more advanced tuning effort.

Also, if you are installing used Zeniths for your engine then there is the possibility that they may not be a matched set; emulsion tubes are slightly different and the progression circuit holes are not identical in sequencing and diameters for different model years.

[frosty2]

Thanks Paul I will get three more 195's so at least they are all the same
and start there.
Also I'm not adding the zeniths to my car they are the ones that were on
there but the car sat in the PO's garage for twelve years so I am just doing
the rebuild to clean them up and just finding some little quirks along the way
from what was likely an ealier rebuild.

Yhanks
Mike

[ivory911]

With regards to the gaskets: the PET has a good exploded view of the Zenith with gaskets and all. That sandwich gasket looks like it is supposed to go on the bottom of the intake manifold. I think they are NLA (or at least I hope they are because I just bought the normal one-piece type). I am also rebuilding my Zenith's at the moment and I am going through the same things.

The factory manual has all of the original specs written down for jets and such. Do you have access to a factory manual? If not, I can post up the list for you. I want to say that they originally come with 185's but I am not sure if that's only for the 2.0L. Do you have a 2.2 or a 2.0 in the car?

By the way, where are you getting your jets from? I need to find a good source for that stuff.

[1QuickS]

eBay has a Zenith parts seller in Italy "Alfa1750"

[frosty2]

Hi Tyler no I don't have access to the factory manual so if you could post it that would be very helpful.
My engine is a 2.4 so I think the solex 195 jets might be the right ones to start with.
My cabs originally had solex 47.5 idle jets and I changed them to #55's and
it made it a lot easier to set the idle.
As Paul mentioned the zenith parts are available from alfa1750 on ebay and they
are also available from geneberg.com.
Thats were I got my idle jets from and they also list the main air jets and there is a phone number on his site so ther easy to get a hold of.
If you are just starting the tear down remember to make lots of notes.
I first went to Canadian Tire and bought myself a small plastic parts box that has about sixteen compartments cost was about $4.00 and it worked great to keep all the Little pc's separated. Put little pc's of paper in each one with a description and part number from the blow up I downloaded from the forum.
Drew myself a good size picture of the side view and one of the top view and then just drew each part I was removing on the picture and put description and number on there as well and it was fool proof for re-assembly.
At least until I go to start the car anyway.
Sorry for the rambling it just worked to easy for me not being a mechanic.

[rw7810]

The "hard spacer" in that gasket stack was put there by the factory as a heat insulator to help prevent engine heat from boiling the fuel in the float bowls.

[frosty2]

Thanks Bob in that case I will leave them there.

Thanks
Mike

[ivory911]

Good to know about the spacer. That may explain my vapor locking problem

Thanks so much for the parts sources! I am going to look into that. Good tip with the plastic box; at first I didn't want to do that, but the longer the parts sit around in my shop, the more likely I am to forget where they go.

So, I took a look at my manual today. Unfortunately, it doesn't cover the 2.4 for the carbs (just up to 1970). I'll list the specs anyways. They are as follows:

From Sep. 1969 - Mar. 1970
-venturi- 27.5
-main- 115
-air correction- 185
-emulsion tube- 4mm dia.
-idle fuel jet- 47.5
-idle air bleed- 140
-injection qty- 0.5 +/-0.1cc/stroke

From Mar. 1970- Sep. 1970
The only changes are:
-air correction- 195
-emulsion tube- 4.3mm dia.
-idle air bleed- 155 (165 for US cars)

From Sep. 1970 on
The only changes are:
-main- 110
-air correction- 170

I don't know if that helps you but hopefully it will help someone.

[larrym]

whi you are at it - the best way to get these tuned right is to install a wide-band sensor kit

and get a boxfull of jets to experiment with

.

[frosty2]

Thanks Tyler that is good reference info

Yes Larrym you may have good idea there. Think I'll Waite till spring and see how things goes