[southcoastmusta]

I have rebuilt my 1965 Autolite 4100 carb twice now, with brand new gaskets and seals throughout.

The car struggles to start and when it does, there is a distinct inability to maintain its idle at any RPM.

I have had the car running with a brand new Edelbrock carb, so I know that it is a carburettor issue. The timing is set, and the engine is a fresh rebuild with new gaskets throughout.

I have not touched any idle jet, nor the mixture, as I wanted to post something here first before trying anything else.

So, if anyone can shed some light on how to get this carb running as new & tune it, please reply.

Pictures:

http://www.buyconfidently.com/southc...s/DSC00061.jpg


http://www.buyconfidently.com/southc...s/DSC00064.jpg

[tripleblack]

So, you tried to rebuild the same carb twice?

I would suspect the float - did you check it for leaks?

[The Greek]

Change out the power valve with another rated for 6.5" of vacuum. The Holley power valve will work on the 4100. The small rubber diaphram in the valve will rupture from age, defect or a backfire through the carb. Holley sells the power valves separately.

[Scott Amann]

Just out of curiousity, what is the carb number stamped on the foot of the carb?

I recently purchased a 4100 carb that I have been told will not run on my stock 289 rebuild as it is from a 66 Galaxy - FE motor. I was told that it would not idle properly as it was set up at the factory for a larger engine.

[Mn66emberglo]

If you dont get a smooth operation at any RPM I would start with your idle mixture screws first. There are 2 in the front of the carb one below the fuel filter and one below the accelerator pump. Turn them in all the way until they just start to get tight. Do not tighten all the way!. Turn the screws out 1 and 1/2 turns for each. Doing this you are going from a lean to a richer mix. If the mix is too lean it will idle rough at every RPM.

If you can smooth out the idle a bit that the car runs then let it warm up and adjust the hot idle RPM by the screw on the accellerator linkage side. This should adjust hot to 500-600 rpm.

Next go back and set the cold idle rpm by pulling up the choke linkage until the car revs higher. Set the screw on that side to give 1600 RPM. If you have an automatic choke that also needs to be set that is another adjustment but first see if you can find a condition to keep the car running

reset the choke down and check the timing. Should be around 6 degreed BTDC. Next go back and on the idle screws turn the one under the fuel filter out until you see the engine smoothing out on idle as best as it can. Then turn out the other screw the same number of turns to adjust the secondary carb. Finally adjust your dashpot to .6MM

this should get you in the ball park. Next you may need to adjust the idle or timing a little if you find on accelleration you have a dead spot. If the cold start is a problem there are adjustments to the auto choke and the choke plate that can help.

[dutchcarson]

From the look of your pictures, it appears the carb sat around for awhile and got pretty dirty. Did you competely dismantle the carburetor and thoroughly clean out every little orifice with carb cleaner and compressed air?