Looking for Autolite 4100 rebuild tips and techniques.

[cleandan]

I will be refurbishing an Autolite 4100 (1.12)
This carb sits atop a 289 in a 1965 CSX street cobra so originality is important in this case.
I have rebuilt many of the 4100 series carbs and realized I have never really asked anyone about them.

Do you have any "do's and dont's" I could benefit from knowing?
Is there a better place to get parts for a 4100, if needed?

I purchased my rebuild kit from Cobra Automotive because they put together the various parts to make a comprehensive kit, but I don't know of anyone actually making a full rebuild kit anymore.

The 4100 is a good carb and pretty straight forward to refurbish, but still, have you got any tips to make my finished product even better?

Thanks and have a great day.

[Towd56]

the only thing I can offer is to make sure all your flat surfaces are actually flat when you reassemble. Things like the acc. pump housing, over the years have been overtightened and have become warped. I usually stick a few pieces of 220 DA paper to some flat glass and run all the surfaces over the paper. You will clearly see by the color of the surface how far out each surface is. Make sure you have the correct length fasteners and don't overtighten them.

There are a few good you tube videos on rebuilding the 4100 - it's a pretty easy carb.

good luck

[Falcon67]

Same - on about any carb.  I keep a piece of 3/8 x 1.5" steel that I can wrap with 320 (or whatever) wet/dry.  Wet it with WD-40 and lightly buff mating surfaces.  I have a Ford 4100 manual but as you know there's not a lot to a 4100.  Good all around carbs.

[mtburger]

I use Mikes Carburetor for all my stock rebuilds.

He has several different 4100 kits, E-Manuals, and videos.

https://www.carburetor-parts.com/search.asp?keyword=autolite+4100

Thanks, Mike H.

[thatdarncat]

I don’t have much for tips, just a couple things for people interested. I’ve always used Motorcraft rebuild kits in the past, you could still get them from Ford not that many years ago, but I haven’t checked in quite a while. A friendly Ford dealer parts department might be able to check on their locator service for any kits out there still if they’ve gone obsolete. Towards the late years Ford consolidated many of the previous kit numbers to just one or two, the C2SZ-9A5586-D was one I used a few times. The Motorcraft rebuild kit doesn’t include the vacuum secondary diaphragm, I found I could get those through NAPA in the Echlin line. It seems I remember it took a NAPA counter person who could use an actual paper catalog to find the part number, and they had to special order them for me, but they were available. The secondary diagram is NAPA Echlin part # 2-4241. The newer secondary diaphragms come with the plastic arm, so for originality if yours has the metal arm be sure not to lose that. It’s possible the full NAPA rebuild kit, if still available, was made by the same manufacturer as the Motorcraft kit, but I don’t know that. Years ago Ford had quite a few jets sizes available, a couple years ago another member was looking for the part numbers and I posted that from the Ford Parts book, I’ll try to find that picture again. There is a company reproducing the Ford Jets, they are available on the Internet and some of the bigger carb parts companies. A common trick for people racing a 4100 is to use a Holley power valve, which has more calibrations available. The primary & secondary booster assemblies usually have a code stamped on them that match a particular carb, the codes can be looked up in the Ford Parts books, if you want us to double check you still have the originals.







Here’s an alternate replacement secondary diagram, I don’t remember where I sourced these Hygrade ones.



Jet info from Ford Parts book

[katink]

X2 on Mike's and the flat surface check including power valve seat.  Also it cannot be clean enough and it will not stay clean enough, my experience.

[cleandan]

Thanks for the replys, I appreciate them.
I do know a good amount about these carbs, and I have a few different pieces of glass I use for flat surface prep work too, but if there is one things I know for certain it is I don't know it all.

This means I can always learn something new if I look in the right places.

Because this carb is part of a significant vehicle I am simply checking all my options to make certain I come up with the best result I can.

The part manufactures and part numbers are always a HUGE help when it comes to finding the right stuff these days....especially when I have to go to the local auto parts stores.

The people working there may be good at what they do but they are hamstrung by poor computer information and even fewer options when it comes to looking up old car parts.
If I can start with good numbers then cross references, other books, and options become much more useful, otherwise I am left trying to explain to them some manner in which they can look up the parts that the computer recognizes....and that gets old, especially when there are now six people in line behind me waiting.

The replies either provided me with useful information, or confirmation that I am doing things well already...all good and all appreciated in my mind.

Thanks and have a great weekend.