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Old 12-07-2020, 01:34 PM   #1
Oldgearz
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Default Position of Indicator on Choke/GAV Rod

Now I know this doesn't really affect how the car runs, but in what position should the little indicator on the choke/GAV knob be in when the GAV is closed?
It just dawned on me that the last time I had the carb off I didn't pay any attention to this when I reconnected the GAV rod, so my smoothest running position changed by 180 degrees. I thought that was caused by the rebuild I did. My GAV is currently closed at 9:00 o'clock. What was the setting of the indicator when it came from the factory?
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Old 12-07-2020, 02:16 PM   #2
Gary WA
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Default Re: Position of Indicator on Choke/GAV Rod

Mine all are at 9 oclock position when closed
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Old 12-07-2020, 02:31 PM   #3
abachman3
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Default Re: Position of Indicator on Choke/GAV Rod

It is really an arbitrary position. It depends on the carburetor choke driver and its seated position. They are not all the same due to how far into the carburetor one tightens the driver seat.
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Old 12-07-2020, 03:08 PM   #4
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Default Re: Position of Indicator on Choke/GAV Rod

I've had the knob come lose on the rod. I paid NO attention to its orientation when I secured it again but it could have been anywhere.
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Old 12-07-2020, 03:58 PM   #5
J Franklin
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Default Re: Position of Indicator on Choke/GAV Rod

There is no proper orientation. It all depends on where the knob ended up in manufacture and what carb is used. Turn the GAV as near closed as the engine allows.
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Old 12-07-2020, 06:26 PM   #6
Oldgearz
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Default Re: Position of Indicator on Choke/GAV Rod

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Thanks all. I'l stick with 9:00 o'clock.
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Old 12-07-2020, 06:53 PM   #7
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Default Re: Position of Indicator on Choke/GAV Rod

Our 29 with a Zenith 1 carburetor is closed at 4:00.

When you close it, don’t snug it down tight.

Enjoy.
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Old 12-07-2020, 08:59 PM   #8
J Franklin
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Default Re: Position of Indicator on Choke/GAV Rod

Quote:
Originally Posted by Oldgearz View Post
Thanks all. I'l stick with 9:00 o'clock.
If you do that you may end up running too rich or lean. Set it where the car runs best considering the conditions, cold more open and warmed up fully it may need to be fully (not tight) closed. the knob will be in the clock position it needs to be.
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Old 12-08-2020, 10:29 AM   #9
Purdy Swoft
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Default Re: Position of Indicator on Choke/GAV Rod

Mine are usually at six oclock when fully closed . Most run good at three oclock after a brief warm up .
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Old 12-08-2020, 01:22 PM   #10
DBrer
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Default Re: Position of Indicator on Choke/GAV Rod

Closed at 1:00, runs nice at about 11:00
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Old 12-08-2020, 02:59 PM   #11
Ed in Maine
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Default Re: Position of Indicator on Choke/GAV Rod

Just to add another variable to this discussion, it also depends on the size of the Main Jet. Published flow data indicates that this jet (which is directly connected to the carburetor bowl) is 150 ml/min to 160 ml/min. I have found that when I rebuild a carburetor that has a Main Jet calibrated at 160 ml/min, that it greatly reduces the need for the GAV to be open. Note that the GAV is putting gas into the Cap Jet that is next to the Main Jet in the carburetor throat. Well, this is no fun because part of the fun of driving a Model A is adjusting the GAV to meet the driving conditions. Now, I strive to set the Main Jet at a flow rate of 156 ml/min or less down to 150 ml/min so that some supplemental gas from the GAV is required. I like J Franklin's take on all this, "the GAV will be at the clock position it needs to be". Ed
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Old 12-08-2020, 03:33 PM   #12
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Default Re: Position of Indicator on Choke/GAV Rod

It's 5 O'clock somewhere.
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Old 12-08-2020, 06:44 PM   #13
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Default Re: Position of Indicator on Choke/GAV Rod

From the owners manual for late 1931 and early 1931 see the GAV rod position
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