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

 

[mike657894]

on my car its a tilly but similar concepts. I get pops on acceleration if I have my gav closed. I have read that the gav is full open at 1 turn out. and any turning beyond that is the same as 1 turn out. I take mine full out for starting. it will smell rich in the exhaust. I would suggest taking off the carb and really blasting out passages with carb cleaner and compressed air. Wear safety glasses. I say that because im stubborn about putting them on and get a blast of cleaner at my face nearly every time then put on the glasses. With the stalling at stops your mixture screw on the side of the carb could probably come out a bit. Or also dirt or debris causing less fuel flow.

 

[Bob Bidonde]

My practice is to set the GAV 1/8th of turn open, get the engine to operating temperature and then make carburetor adjustments. The only time I turn the GAV OFF is when cruising at highway speeds for long distances on flat roadway and over 45 mph.

 

[Tom F OHIO]

My practice is to set the GAV 1/8th of turn open, get the engine to operating temperature and then make carburetor adjustments. The only time I turn the GAV OFF is when cruising at highway speeds for long distances on flat roadway and over 45 mph.

Does your car run better that way or do you get better gas mileage by doing that.

 

[Tom F OHIO]

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

Marc for a piece of mind I would clean the carb out. But if its running good where it is at then maybe this is how your carb works. When I start mine I go half way and then a quarter turn and it smoothens right out. I feel each carb is going to be different.