I have 2 Autolite 4100 4-barrel carburetors with stuck throttle shafts. Does anyone have any new ideas to free the stuck throttle shafts without destroying the aluminum carb bodies? Many thanks to all of you in advance. Thanks again, jack
Yes, rebuild them. Take everything apart, and what you can't free up spray with penetrating oil. . . if it's still stuck just put it all into a bucket of carb cleaner and wait a day or two.
I had a valuable AFB that was stuck. I drilled a tiny hole from the bottom up to the shaft until the chips turned a different color, then soaked with PB Blaster for about a week. It freed up very well.
We have successfully used an ultrasonic cleaner. Those that don't come loose after the ultrasonic come loose with controlled heat. Jon.
Another thing...Evaporust. I think this is about the only deruster that won't hurt zinc or anything else in a car. You can safely drop in a complete carb. It will at least clear the neighborhood on the shaft, and it does have some limited penetrating ability from surfactants in the mix. Carb shafts in general have a bit of endways play, and tapping them sideways in both directions will sometimes get things started.
The only thing I have had work is carefully heating the steel throttle shafts, then cooling with ATF. Dissimilar metal corrosion can be a bear to unfreeze! ---John
There is no substitute for time, you gotta let it soak for a few days in carb cleaner or other non corrosive chemical, I have had some luck boiling carb parts in water and then allowing them to cool, the expansion and then shrinking free's them up.
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