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autolite 4100

 
Luke65
User
Posts: 123
Joined: 06/09
Posted: 11/26/12 01:05 PM

Can anyone provide me with a detailed  diagram of a autolite fortyone hundred  for breakdown and rebuild  

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bucala
New User
Posts: 36
Joined: 03/10
Posted: 11/26/12 06:50 PM

Autozone has repair guides online with a full breakdown.  I scanned the whole section on the carb, but I can't post it for whatever reason.

If you don't find what you need, PM me, I have a full shop manual.  

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bucala
New User
Posts: 36
Joined: 03/10
Posted: 11/26/12 06:50 PM

http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/27/a1/8a/small/0900c1528027a18a.jpg  

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Luke65
User
Posts: 123
Joined: 06/09
Posted: 11/27/12 06:26 PM

Is there a correct setting for the 2 screws on the bottom of the carb that have spings on them?  

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waynep71222
Enthusiast
Posts: 455
Joined: 04/12
Posted: 11/28/12 12:04 AM

carb on the bench... 2 1/2 turns out is a good starting point..


setting the idle mixture is done with a screw driver and a vacuum gauge... sometimes a tachometer.. so you can set the proper idle speed...

do you have a vacuum gauge...
Fuelpumpvacuumtester


its a balancing act on the engine...

get the engine warmed up...

hook up the vacuum gauge to a manifold vacuum port...

make sure that the choke is fully open and the fast idle screw is no longer contacting the fast idle cam steps...

position the vacuum gauge to allow easy viewing while adjusting the mixture screws..

turn one screw in a little at a time until the engine starts to slow down or the vacuum drops..  turn it out until you reach the highest vacuum reading.. stop..  turn it back in till the vacuum starts to drop again.. take it back that tiny amount till you get it just at the point the vacuum started to drop...

go to the Other screw...

turn the other screw in a little at a time until the engine starts to slow down or the vacuum drops..  turn it out until you reach the highest vacuum reading.. stop..  turn it back in till the vacuum starts to drop again.. take it back that tiny amount till you get it just at the point the vacuum started to drop...

if the idle speed is wrong.. reset the idle speed.. and

go back to the first screw again..

do the second screw again...

once you get both screws to the exact point where the manifold vacuum is about to drop.. turn the idle screws in a tiny amount until the overall manifold vacuum drops 1/2 inch of vacuum..

it could be 1/4 or 1/3  of a turn each.. sometimes its only 1/8 of a turn..

this is lean best idle...

if you change the idle speed.. to get the best fuel economy . you will really want to break out the vacuum gauge and reset the idle mixtures again..

this was taught in autoshop decades ago..

if your idle mixture screws don't react.. and you have rebuilt the carb.. i have some images for you to view with tiny passages that you may need to clean and verify they are open..  

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waynep71222
Enthusiast
Posts: 455
Joined: 04/12
Posted: 11/28/12 12:17 AM

here are a few images that you will want to review..

this is the accelerator pump discharge nozzle..  
2100Pumpdischargenozzle


these are some of the idle circuit passages... that need to be verified that they are NOT clogged with debris... the wire i used is 0.023 stainless mig welding wire..  just because i had some..
some carbs might have smaller passages .. so you might need to pull a bristle from a wire brush..
2100Idlecircuit2


this is the main circuit air bleeds...
2100Maincircuitairbleed

more of the main circuit...
2100Maincircuits  

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mechanicalguy48
Guru
Posts: 854
Joined: 12/07
Posted: 11/30/12 04:29 PM

Those really are excellent pics Wayne,,,, they show correctly the idle jets/Idle channel restrictors and bleeds. I think you should also show the idle ports below the throttle with the screws showing and then show the transition slot and how it is uncovered slowly as throttle opens. I remember helping a little with those a couple years ago,,,but you have a good grasp of that carb. The position and size of the transfer slot can really affect driveability. So many guys use a hot cam which requires opening the throttle more for a higher idle which in turn exposes too much of the transition slot,,, then they get a flat spot off idle.  

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cushman350
Enthusiast
Posts: 648
Joined: 07/06
Posted: 12/01/12 09:22 AM

This discussion should be posted as GROUND ZERO,when attempting tuning your engine. If the idle transfer slots are not being engaged correctly, everything else you attempt, timing, just adjusting the idle, will be in vain. More people waste more effort, overlooking this tattle tale sign.

Something that concerns me now that I have a T5 OD, and chnged to a 350 ratio, crusing at highway speeds, I'm barely off idle and think I may be actually cruising too near the idle curcuits and wasting fuel. Maybe a smaller carb to get the butterflies further away from those transfer slots? Oh, I'm running a Holley 650 now.

cush  

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Luke65
User
Posts: 123
Joined: 06/09
Posted: 12/02/12 05:09 PM

CARB FINALLY SWITCHED now I have more questions.
  So I switched my intake and carb over from an edlebrock setup to the origonal intake and carb that came on my 65 289 coupe. First i hooked up everything and i was wondering if the vaccum advance for the distributor is supposed to be connected to the vac port on the passenger side of the carb? Then how do i go about tunning the carb it started right up but it stalls when i push the accelerator and it is making a loud sucking noise also it is smoking out the exaust alot and it smells like fuel so i am wondering how to tune it since right before i switched it from the edlebrock setup everythings was A-OK.

Thanks for any input!  

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waynep71222
Enthusiast
Posts: 455
Joined: 04/12
Posted: 12/02/12 07:54 PM

wow...

you guys want to know it all... well i am up for it....

stay tuned... and pay attention... this took me a LOT of years to figure out... and gather...

carb guys don't let this out usually as they either want to keep it a secret or don't understand it.. i have not figured out which...

at idle...  the fuel mixture comes out the idle holes.. controlled by the idle mixture screws..

at the top are idle air bleeds.. this prevents the vacuum coming through the idle holes below the almost totally closed butterfly from pulling a straight stream of fuel in...  with the idle air bleeds working CLEAN.. the idle circuit pulls a limited about over..  as its like a hole in the side of a straw.. you can still get your soda but its going to be proportional... the faster you pull the more you get.. but it will not be a solid flow..  and in a carburetor .. you don't want a solid flow.. you want proportionality..   faster air flow.. more fuel..

coming off idle..  the throttle blade exposes more of the idle transition slot... allowing vacuum to pull fuel from that slot...  idle transition circuit stays with you till somewhere between 1800 and 2400 rpms.. at that point the throttle blade is far enough open that the vacuum across the idle transition slot is not enough to pull fuel from it... so it will be running on the mains only.. pulling fuel thru the main circuit ...

as you increase the throttle opening past idle and idle transition.. the idle transition is mostly the circuit that is supplying fuel...

go a little farther..  and the mains start flowing as the air speed thru the venturi lowers the pressure and drags the fuel up and over...

the main circuits also have air bleeds... these main air bleeds and circuits are separate from the idle and idle transition...

many people complain of a flat spot off idle... they start changing jets... metering rods and power valve springs..  but if you are on the idle transition circuit.. this tuning is wasted...

lets look at these images.. don't worry that its for a different carb.. theory is the same..

32 36Idlecircuitatidle

then lets look at the part throttle circuit..

32 36Idlecircuit Partthrottle

Holley 4150 4160 Idlecircuit2 Zps1ffa8cfd

Idleandtransitioncircuit

Transferslot  

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waynep71222
Enthusiast
Posts: 455
Joined: 04/12
Posted: 12/02/12 08:26 PM

CARB FINALLY SWITCHED now I have more questions.
 So I switched my intake and carb over from an edlebrock setup to the origonal intake and carb that came on my 65 289


ok... i am taking that you rebuilt the carb...  and that you took it apart as in the directions. without pulling the throttle blades off the shafts... as thats not needed .. but most of the other parts come off..

please describe what and how you did the carb work..

Then how do i go about tunning the carb it started right up but it stalls when i push the accelerator and it is making a loud sucking noise

loud sucking noises are Vacuum leaks... you will need to find them...

you could also need to check the alignment of the throttle plates on the throttle shafts..
please do not attempt to remove the screws .. they can be SLIGHTLY LOOSENED...

also it is smoking out the exhaust alot and it smells like fuel so i am wondering how to tune it since right before i switched it from the edlebrock setup everythings was A-OK


i will have to look at my parts books... did you replace the 2 different gaskets under the carb??

the NON high performance 289 4bbls use a felpro 60069

the HIGH performance 289 4bbls use a felpro 60046

either application uses 2 of them .. one above the the spacer and one below the spacer...

got pictures???

lets look at the accelerator pump circuit...

engine slightly warmed. 30 seconds from cold will ***   engine off... take a look either straight down into the primary bores while holding the choke blade open...  move the throttle lever off the idle stop...  this is still engine off...  do you see a squirt from the center of the booster venturi..

look at this image... it shows where the accelerator pump should be discharging fuel from when the throttle is being opened...  there is a hollow screw.. through the central round hole.. a short length of aluminum bar.. and a check ball under that... so the air flow cannot empty the accelerator pump circuit....

2100Pumpdischargenozzles


answer some of the questions i have posted.. lets go from there..  

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waynep71222
Enthusiast
Posts: 455
Joined: 04/12
Posted: 12/02/12 10:44 PM

did you get a chance to read this article on the 4100 right here in the magazine..


http://www.mustangmonthly.com/howto/mump_1201_autolite_carburetor_rebuild/


be sure to click through the individual pictures..
as each one has text below it..  

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Luke65
User
Posts: 123
Joined: 06/09
Posted: 12/03/12 01:11 PM

When I rebuilt the. Carb I replaced all gaskets as well as the vaccum secondary diaphragm. I changed the spacer gasket and tha not only stopped the sucking noise but smothed out the idle some now I am trying to figure out if the vaccum line from the trans connects to the port on the rear of the intake and does the vaccum advance connect to the passenger side of the card in the threaded hole near the bottom of the carb and if so what kind of brass fitting or other fitting should be screwed into that threaded hole in order to connect the vac line from vac advance to the carb?  

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cushman350
Enthusiast
Posts: 648
Joined: 07/06
Posted: 12/04/12 03:04 PM

The type of distributor dictates what vacuum port is used. Some need 0 at idle, other need full vacuum at idle. One port supplies access to vacuum above the butterflies and the other is suppling vacuum from below. Usually has to do with emission and non-emission dist.  

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Luke65
User
Posts: 123
Joined: 06/09
Posted: 12/05/12 07:26 AM

So I guess my question becomes witch is mine the carb was origonaly removed and replaced with an eddlebrock setup and I have just replaced it . When it is at idle the port that is open is on the lower passenger side front and it has full vaccum at idle and the eddlebrock it was running also had it connected to a full vaccum port. So what I am wondering is what size hole is it so that is may get something to put in it to connect my vac line to or is it a actual part I can order not just a brass fitting.      Thanks so much for all the help  

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