Originally Posted by DaveRS23
Originally Posted by Craig J
I like AFB carbs. I am not sure why, probably because so many people seem to hate the later Edelbrock versions, in particular the 1407 that have a terrible off idle lean spot after the transfer slot is fully exposed but the main circuit has not started flowing.



The CarterBrocks are not bad carbs, it's just that their tunes are antiquated and they are much more work to dial in than their competitors. Just like you are finding out.

Can anyone answer why they have never done any updates to their circuits when their problems are so well known?


The issue with the late Federal Mogul and Edelbrock 750 carbs is they use the wrong length booster in the primary. If you look at an earlier "correct" Carter 750 you will notice the booster is longer and that places the booster where it actually needs to be which is just after the minimum restriction of the venturii. I have swapped boosters and logged where they begin to flow after the transfer slot slows stops and from memory its was around 500 rpm so thats where the dreaded lean issue comes from. You can raise the float level a little to get the primary booster to flow sooner.

If it were me I would make them have 4 transfer slots 2 pump shot wells and convert them to solid fuel metering. win win win.


Last edited by hysteric; 09/30/22 05:57 PM.