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Anonymous
Guest
Pardon my ignorance, but what are the two screws that you adjust for?
Thanks
Thanks
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Anonymous
Guest
I believe you are refering to the air / fuel mixture screws.....where are they located?
New Lime 69
Active member
There are only two adjustable screws on that carb. The first at the base of the carb is the air/fuel mixture. The second is the idle speed adjust on the back of the carb. near the choke. Hope that helps.
Chris
Chris
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Anonymous
Guest
does anyone have a good method of getting the air/fuel mix to best lean mixture? i have a Carter YF, i think i have it set but if some one has a tried and true method they use the advice would be appreciated.
Thanks in advance
Thanks in advance
Check out http://65coupei6.mustangindex.com under Tech
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Anonymous
Guest
I can't say I am an expert on that particular carb however from what I can remember the goal of adjusting the idle-mixture screws is to achieve the highest possible idle vacuum at a set idle speed. With that said if there is a place to connect a vacuum gauge to measure manifold vacuum on the carb, then set your idle speed around 700rpm turn the mixture screw in snug and back it off about 1-1/2 turns and start there. Take note of the pressure then turn the screw in 1/2 turn and see if the pressure increases if yes repeat until you have the highest possible pressure...if no then back it off 1/2 turn until you have the highest possible pressure
Note if your idle increases or decreases (wich is likely) then reset the idle to its original start point to make sure you are consistant.
By the way the engine should be warm or "normal operating temp"
Note if your idle increases or decreases (wich is likely) then reset the idle to its original start point to make sure you are consistant.
By the way the engine should be warm or "normal operating temp"
A
Anonymous
Guest
The base screw is for air/fuel, if I turn it clockwise, which is getting more? Air or the fuel? I know if I turn the idle screw it decreases, got it by ear. But for the air/fuel screw, how does it works?
There are three screws and a nut to turn on an Autolite 1100.
First is the idle set screw. It sets the throttle blade opening to set idle speed.
Next is the idle mixture screw. It is the screw on the base of the carb. Turning it in leans the mixture, turning it out richens it. It only affects idle mixture. Start by turning it out 1 1/2 turns and then adjust from there to get best idle vacuum. Do not overtighten it all the way in. You will damage the needle.
Then there is a choke setting nut. You have to insert a drill bit into the carb opening as a gauge (size depends on carb and car model), and then you adjust the plastic nut to get the blade to the proper setting.
Finally, there is a fast idle set screw. It is attached to the throttle lever and is activated by the choke idle cam. When the choke is on, the cam pushes this screw which alllows the throttle to open more than normal to give you a fast idle until the engine warms up.
I gotta tell you though, you need a manual. I can describe these screws all day long, but until you see the step by step procedures in pictures, you will not understand. You can usually copy the pages you need in the library if you don't want to buy one, but I think more prople have screwed up their carbs settings (no pun intended) by trying to follow internet advice on this stuff.
First is the idle set screw. It sets the throttle blade opening to set idle speed.
Next is the idle mixture screw. It is the screw on the base of the carb. Turning it in leans the mixture, turning it out richens it. It only affects idle mixture. Start by turning it out 1 1/2 turns and then adjust from there to get best idle vacuum. Do not overtighten it all the way in. You will damage the needle.
Then there is a choke setting nut. You have to insert a drill bit into the carb opening as a gauge (size depends on carb and car model), and then you adjust the plastic nut to get the blade to the proper setting.
Finally, there is a fast idle set screw. It is attached to the throttle lever and is activated by the choke idle cam. When the choke is on, the cam pushes this screw which alllows the throttle to open more than normal to give you a fast idle until the engine warms up.
I gotta tell you though, you need a manual. I can describe these screws all day long, but until you see the step by step procedures in pictures, you will not understand. You can usually copy the pages you need in the library if you don't want to buy one, but I think more prople have screwed up their carbs settings (no pun intended) by trying to follow internet advice on this stuff.
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Anonymous
Guest
Mustang Six, there is also another home tune up for the air mixture if you have a tach. You may have to remove the air cleaner mounting thing on the top of the carb I think its held in by two screws . You may need a buddy to watch your tach if you dont have a remote dwell tach tester. Anyway, while observing the rpm slowly block the air intake of the carburator with a flat piece of cardboard. If the air/fuel mixture is correct, the rpm should not change until the intake is almost blocked up. If the rpm increases the mixture is lean, if the rpm decreases the mixture is rich. Readjust the idle mixture screw accordingly. It works for me----Larry
Good trick. Still, I think that everyone (especially me) needs a manual on hand to refer to for pics and specs. Without one, you really handicap yourself.
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