pull out a vaccuum gauge install on vaccuum port of carburator start vehicle use adjustment screws to pull the most vaccuum as possible on each port,repeat process on second port once adjusted press throttle to around 2000 r.p.m.'s to determine where vaccuum gauge needle is operating at.
They have their units designed to have a 3% inrichment in all curcuits, because they "felt" that everyone would have a Hopped-Up engine to put them on.

The #1 thing that is a culprit on the AFB is float adjustment, either to high or to low, it will cause issues. To high a setting will cause bleed-over into the primaries, which will result in a ' gassy-smell ' in the shop, and sometimes longer cranking to fire up the engine. It will also over come the 'fine-tuning' of the front screws ( in layman terms) and not allow you to really get the correct mixtures.

To low of a setting will cause a 'lean-out' condition, and also create a 'stumble'.

#2. The 2 screws on the front control the 'fuel' on both the ' idle-curcuit ' and the ' cruise-curcuit ' . If you have these currently at only 1/2 of a turn from seat, and the engine is running this ' rich ', you have another issue.

I'm attaching a picture of how to properly set the float, and the measurement.
I hope this is of some help to you.

One other thing, do NOT gap your plugs any larger than .035 ! ! !
...the #1 problem is to large of a gap.

If I can be of any other assistance , Let me know.

 

wont idle well.

 

acts like its getting to much fuel like backfiring and flooding itself.

 

I had the same exact problem with my mustang when i built it and the problem was the ground that goes to the bell housing to the firewall wasnt hooked up and the starter grounds to your bell housing so if its not there its ground sucks

 

itll run fine one minute the next it acts like its running on 4 cylinders i tried timing it and got the carb adjusted its still running like crap BUT ONLY SOMETIMES.
is this a wiring issue?????????

 

what type of ignition set up are you running??

 

the stock one.
havent touched it since ive bought it.

 

might buy a new carb or rebuild mine any ideas or suggestions.

 

intermitent running bad may be the ignition system, like the module or stator in the dizzy??...you need to narrow issue down to the fuel system or ignition

 

did you check the ground strap going from the motor to the frame? Do you have the spout connector plugged in?check ALL your wiring connectors under the hood.