AUTOLITE 4100 TAGGED C4GF RATED AT 1.12

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diemert66@gmail.com
Posts: 6
Joined: Thu Aug 27, 2020 2:54 pm

AUTOLITE 4100 TAGGED C4GF RATED AT 1.12

Post by diemert66@gmail.com »

Hey guys, Has anyone had any experience ( read TROUBLE) with the cyclone 1.12 Autolite C5 GF ? I have rebuilt two of them in my shop for customers and had complaints about both. I've rebuilt over 200 4100s both 1.05s for mustangs and 1.12s for other vehicles. We all know that these carbs are pretty much year and model specific and more often than not the fault lies with the user not the carb, but to have two of these returned is pretty rare, I accept that I have screwed up the rebuild somewhere, I would just like to have some input on where I'm going wrong. I use my shop manual and videos exclusively As usual thanks for all the input. What a great site this is! over the years I've come to rely on this dozens of times!
Kind Regard, TOM

vicegrip
Posts: 360
Joined: Tue Jan 08, 2013 11:12 am

Re: AUTOLITE 4100 TAGGED C4GF RATED AT 1.12

Post by vicegrip »

What exactly were the complaints?

barrys65cyclone
Posts: 571
Joined: Mon Aug 27, 2007 1:54 pm
Location: maryland

Re: AUTOLITE 4100 TAGGED C4GF RATED AT 1.12

Post by barrys65cyclone »

Tom
First off did you verify it is correct for application ? 1.12 for Cyclone would be for 1964 { C4GF } once correct carb is determined verify correct boosters & other calibration parts correct ? next is engine factory stock ? then we can take it from there.

HIPOComet
Posts: 4
Joined: Sat Feb 09, 2013 9:47 am

Re: AUTOLITE 4100 TAGGED C4GF RATED AT 1.12

Post by HIPOComet »

Previous posts on determining if the booster venturi assemblies are the correct part number (pri. letter codes Y, L & KA. Sec. code B) as well as the jet sizes is good advice. The take 'em all apart and throw 'em in a pile approach of rebuilders causes problems. In my 70's auto shop class we students we're employed (for free!) to do this type of dis-assembly for a local parts rebuilder. If it's the C4GF 1:12 venturi 4100 carb used until about 4/64, then it has the longer accelerator pump "nose" with the check-ball and screw on top. That pump uses a cavity filler plastic piece that's sometimes left out of a previously rebuilt carb. Or if it's in there how's it holding up to the blended gas the owner is using? The wide part of the conical spring goes against the diaphram. If it's a 4/64 and later redesign 4100 with the shorter "nose" and an orange elastomer diaphragm, how's that holding up to the gas? Spring in correctly? Now the wide part of the conical spring goes against the carb. Good luck!

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