zenith leak

[mak]

The front zenith carb has a slight fuel dribble from the atomizer area .
I have replaced the needle valve. The fuel levels are correctly at 22 MM in both carbs ,still the dribble .any thoughts on a solution
Thanks
mak

[daidnik]

I think my terminology is right here. This terminates in a brace with a donut and straddles across the venturri.

I assume that you mean that you see some dribbles at idle from the brass end of the emulsion tube in this area.

If so, I'm not sure that this is an anomaly.

I no longer have my 108, but I do recall this same sort of thing on those Zeniths. The important thing is to have the airflow thru the venturri balanced or equal between the two carbs; done with the air-flow gauges or Uni-Syn tool, and the idle mixture balanced or equal on the two carbs. Adjustment of these two parameters is interactive, so it's an iterative process.

Since there is air-flow thru the venturri at idle, the partial vacuum at the open end of the emulsion tube would reasonably cause some amount of suction of fuel from the float chamber.

[mak]

Thanks .Yes its also listed as a Preatomizer in the Zenith parts section. Only the front carb has the occasional dribble not the rear one, and when it does, it upsets the idle smoothness for its duration.
I have been using a German make Carb synchronizer i got from JC whitney and works very accurately .
regards
mak

[ctaylor738]

Been a while since I dealt with the Zeniths, but this is usually a plugged idle air passage. This is where the air would normally come from at idle but if it is plugged, the vacuum will pull fuel through the main jet system.

[Ritchie]

Originally Posted by mak

I have been using a German make Carb synchronizer i got from JC whitney and works very accurately.

I just got one of those and it is a great flow meter. I got a Uni-Syn first. The "made in china" one. It is no good at all.