I remember watching that VHS tape that Pony Carbs puts out about the Autolite 1100. The tech doing the demonstration was pretty insistant about using a vacuum gauge to set it up. I have since lost the tape after loaning it to someone.

Does anyone know the process Pony suggested? As far as I can tell I can only adjust the idle screw in or out and raise or lower idle RPMs in the process.

I have removed the choke mech in favor of a simple hand choke. The fast idle screw is still there.

Any help will be appreciated.

Harry  

The three screws, two on left side of carb are idle screws. Fast and slow idle. One is the idle speed of engine while warming up, the other idle speed once the engine has warmed up. The other screw is the idle circuit air fuel mixture. I adjust this mixture, once car is warmed up, by ear so to speak. Turning the screw a little and see if the car idles smoother. The proper way is to use a vacuum gauge, and adjusting for the most vacuum. Back to idle once warmed up, if you have an automatic tranny the car should be in gear. So you will need a helper. Turn idle screw until the engine is at 600 RPM's. The choke also has an adjustment by turning the big black cover on the side of the carb. Do a search for fordsix.com tons of info for these six cylinders. Good luck!  

That's sorta how I remembered it. My engine is cammed up but will idle as low as 450. I'm supposed to get it to 750 with an automatic. I didn't know about "in gear" thing though. Thanks.

I'll rey it tomorrow!

Harry  

Yeah, 750 out of gear idle will be about 600 in gear.  

Actually the proper way is the way you describe. At the factory we never set idle based on vacuum. It would be too unreliable as it has so many things that influence it. I have heard this method before and I think its sort of an urban legend. Maybe some auto maker used it I dont know, but to my knowledge we never used that method at Ford. Turn the idle screw in (lean) until it starts to miss or lose speed then out until it does the same thing and set it between those two. Generally speaking I used the leanest setting possible, in other words turn it in until it starts to miss and then out a quarter turn. The engine should be set hot out of gear first ,,then if its an automatic reset it to the spec in gear afterwards. Depending on your initial advance setting this may or may not be the highest vacuum,,,so ignore Pony carbs advice.  

OK, then question me this answer. Most
Autolite 1100 carburetors are poor performers, and that has been documented over and over throughout the years.  All classic Mustang owners with 6 cylinder engines will attest to that. In other words, you factory guys don't have a clue. When Pony Carbs rebuilds them, they run perfectly.  Now, that is the word on the street.  Pony Carbs does something to them to make them run just fine. They charge a lot of money to make them so, but ignoring their advice is not something I would suggest you give to the general public on a Mustang forum.  

Hmmm how to answer this without insulting you. I have known a lot mechanics and most of them know how to make things run,,,they just dont know the why. The factory and the factory engineers know the "why". You always hear this kind of pucky that "they never did run right" or whatever. You can take pony carbs advice, mine is free just like yours soaring. The advice I gave above is the same you will read in the Ford manual, if pony carbs give different advice then I would suggest they are not on firm ground. Its a pretty minor issue, if you use vacuum to set it you have to do it after you have set speed and if it alters the speed then you have to reset it again. You arent going to be way out of the ballpark,,, I am just telling you that the factory didnt use that method and there is no advantage to using it.  

Pony gets their good results by re engineering the carb. They tweek the Holley 1940 too. I don't know what they actually do, but I had my Autolite 1100 rebuilt by them and the results was a great improvement. However, the 1100 they offer as a brand new carb has "annular fuel discharge" what ever that is. This is not done to the rebuilds. Either way, they are better.

I remember when "back in the day" we used vac gauges quite a bit. I had a vac gauge but it sat on the shelf mostly, I pretty much set the idle jets by ear. When, I got the rebuilt carb back from pony last year it had that VHS tape that went into great detail about using a vac gauge. The demo was convincing and the guys at Pony are convinced (and justly so) that most carb problems are actually timing related. Well, I don't know how much effect idle jets have on overall mixture issues, but I'm getting fumes I didn't use to get and gas is $4. I know you can set carbs too lean, but I favor the "leanish" setting just like you.

Does the main jet or the idle screw regulate fuel mixture at 'off idle' speeds?

Harry  

I am sure they do a good job at rebuilding carbs, that is their business. They benefit from over 45 years of carb technology since those were used in mustangs.  Annular discharge refers to the method of adding fuel to the air mixture. In the 50's Ford pioneered annular discharge in their 4100 series carbs. Instead of using a single hole for fuel discharge a booster venturi in the carb feeds gas into the airstream by holes spaced around the perimeter of the booster venturi. You see this in both the 2100 series and 4100 series carbs. That is only part of what makes those carbs the best ever built. My experience was in the 2100 series carbs which I did most of my calibration work. As for the "off idle". The idle system flows much longer then most people think. If you look down the bore you will notice not only the (two in a 2 barrel) idle feed holes but also a transfer slot that is actually a slot cut in the side of the carb about even with the throttle plates. This is what it says ,,,a "transfer" slot meaning it flows in between the main and idle systems and transfers between them. When the throttle bores are closed the slot bleeds back above the throttle plates and does not flow fuel but as the throttle bores open the slot is exposed to vacuum and starts flowing fuel from the idle system. At low flows,,say up to twenty or even thirty miles an hour you flow in this system as the carb transitions to flow thru the main jets. The main system needs significant air movement to create flow thru the main jets. Many many off idle stumble and loss of power problems are related to idle system issues and transfer slot rather then main fuel system. It is the combination of correct advance, accelerator pump shot, and transfer slot action that comprise the smooth transition to acceleration without stumbling. I cant begin to relate how much testing and time goes into a carburetor calibration at the factory. Every change is a compromise, and the factory must build cars that drive well in all conditions. They have the knowledge to do that because they do the design and testing of each piece. No offense to Pony carb but to come back 45 or 50 years later and incorporate changes in the carb that were designed by Ford anyway doesnt make them genuises, just good entrepreneurs. More power to them, I dont think they represent themselves as knowing more then the factory did.  

Good points made by all. I learned all of the above methods, and as a licenesed CA smog tech, we used to set our carbs up based on the hc and co levels from the tail-pipe. Not that that's the best way, it's just another way.  

This morning I went to the guy who borrowed my pony tape and he told me who he loaned it to. I was able to get it back and I watched it instead of the evening news. Here's what "Joe" said to do:
First, check timing. He said to rotate dizzy counter clockwise until highest rpm is found. If the advance diaphram hits the block, pull the shaft and skip a tooth (clockwise). Take a drive, if it pings, back it off about 1/8". Note: I mentioned this method once on another thread and most everyone came back saying that setting timing by ear (RPM speed) alone is not the best way. Well, that's sorta how I always did it anyhow. I didn't even own a timing light in my younger years.
Next, get the engine warm, choke open.
Next, set idle set screw to get 700 RPM idle (automatic tranny).
Next, Turn idle jet screw in until until engine starts to struggle, then turn it out until it struggles again. Set the screw to halfway between the two extremes. Idle will be different then, so reset idle set screw to 700 again.
Next, hook the vac gauge to manifold vac source. It should read between 18 and 21 inches. Said it will be less with a performance cam, but he didn't say how much less.
So, after all that I still don't know what amount of vac my "cammed up" tri power six cylinder 200 should be drawing. I do know all the needle variations/engine condition things associated with a vac gauge. There-in lies the value of a vac gauge.

I was obviously remembering the value of the vac gauge as being more important than it actually was on the tape. However, as the idle goes up from setting the carb correctly, so too would the vac reading. I guess that makes sense.
 
There is much more info on the tape regarding carb types and trouble shooting.

Thanks for that idle circuit screw info. I see that the idle is important, especially to city driving. That would be right in the speed range you said the two systems would overlap.  

Harry