Carb Question
June 19th, 2009, 04:58 AM
#1
all olds...all the time
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Join Date: Jan 2009
Location: Ohio
Posts: 116
Carb Question
I have an Edelbrock 1406 carb that I bought used. I had it on the 403 that was in my Regal and it seemed to run rich in the right bank. I never did get it adjusted right because the motor was not running right at the time. Now that my 350 is rebuilt I would like to adjust my mixture screws back to factory specs before starting the car-I do not want to dump fuel in my new bottom end. Does anyone know where the factory settings are? I read on a few of the "other guys" forums that the setting should be 3 turns out from where the mixture screws seat but I trust my OLDS guys alot more than those "other guys". Any help here would be appreciated.
June 19th, 2009, 06:25 AM
#2
Old(s) Fart
Join Date: Mar 2007
Location: Northern VA
Posts: 47,603
I have an Edelbrock 1406 carb that I bought used. I had it on the 403 that was in my Regal and it seemed to run rich in the right bank. I never did get it adjusted right because the motor was not running right at the time. Now that my 350 is rebuilt I would like to adjust my mixture screws back to factory specs before starting the car-I do not want to dump fuel in my new bottom end. Does anyone know where the factory settings are? I read on a few of the "other guys" forums that the setting should be 3 turns out from where the mixture screws seat but I trust my OLDS guys alot more than those "other guys". Any help here would be appreciated.
June 19th, 2009, 08:18 AM
#3
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Location: Edmond, OK
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A good place to start with a Q-jet is 2.5 turns. Set it between 1 and 3 and then use a vacuum gauge to set the idle mixture screws. Set them for maximum vacuum. You can also use a tach to set them for maximum RPM.
June 19th, 2009, 09:03 AM
#4
all olds...all the time
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The only problem is that I just put a new cam and I need to break that in before I start tuning the carb. I think for initial start up I will turn them out 1 1/2-2 turns.
June 19th, 2009, 09:28 AM
#5
Old(s) Fart
Join Date: Mar 2007
Location: Northern VA
Posts: 47,603
If you are running the engine at 2500 RPM to break in the cam, the setting on the idle screws won't matter. You'll be running off the main circuit at that RPM.
June 19th, 2009, 10:53 AM
#7
all olds...all the time
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Join Date: Jan 2009
Location: Ohio
Posts: 116
I did reset those screws and discovered the right mixture screw was stiff as I turned it in. I pulled both screws out and cleaned the ports with a small brush and throttle body cleaner which solved the stiffness problem. Good point Joe, I didn't even think that it wouldn't make a diff above 2000 rpm. I guess I am just a little wasted with trying to get this together and it being so hot out. Thanks again for all of your wisdom guys!
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