GAV Correct Setting ?

[marc hildebrant]

Group,

A well worn subject, but slightly different.

I have found that the idle performance on my car (rebuilt Zenith in the past) is good with the GAV out 3/4 turn after it "warms up". I do not have a thermostat in the car at the present time. The engine temp is around 150 F.

I have tried many different settings on the idle mixture screw, but at the present time the best is with the mixture screw out about 2 turns and the GAV open about 3/4 turn. With this setting, the car runs well, good "pep" and doesn't stall at idle from a running at speed.

With the GAV closed, I get pops from the carburetor with foot off the throttle and stalls after coming to a stop.

Most instructions say that the GAV should be 1/4 to closed after warmed up...so...my question is :

1. Would a thermostat bring up the temp so that a "standard" GAV setting is used ?

2. Do I even have a problem ?

3. Is the idle part of my Zenith in need of cleaning ?

Marc