After weeks of experimenting and replacing every component known to man; 3 rebuilt carbs, fuel pump, filters, spark plugs and wires, distributor and rotor button, installed Pertronix electronic ignition module and did away with points and condenser, two new vacuum advances, adjusting the timing a thousand times, new fuel lines, ect and so forth. Also, a couple dozen post and replies on here. I awoke this morning at 4am and thought, I am going to drive this thing and when the bucking and jumping starts I am going to ease the manual choke out and see what happens. Well, with the choke half way out it runs like it is supposed to, SMOOTH. HOW CAN THIS BE? OBVIOUSLY A CARBURETOR issue. This is my third "Professionally" rebuilt 2100 Autolite just like the original. I am going to send it back for a refund and buy a NEW HOLLEY. That should do it. I hope!!!!!! Thoughts.????

 

Got to thinking again. It is possible that the jets are the wrong size in the carb or there is a vacuum leak. Gonna check for the leak first.

 

Could be leaking around the throttle plate housing shaft. I don't know if that can be fixed.

 

Yep, I have heard of that. Thanks for reminding me, I will check it out for sure.

 

Look and see what size jets are in it. You could be lean causing too much heat buildup. You probably have 52 or 54 jets. Too small. Either pick up size 62 or 64, or drill the old jets out to that size. This will give you a lot more power, and it actually will give better gas mileage also.

Another thing to check, when this happens, pull over and immediately take off the gas cap and see if you are pulling a vacuum in the tank. The vent in the cap could be plugged up.

 

Why start a new thread on the same problem? See my previous post on your previous thread.