Little rich still

[recessbilly]

I have done a ton of reading, tore apart and cleaned the carbs and rebuilt them multiple times with new gaskets/ needle/seat and now it is running really well on one side, but rich on the other. There isn't gas dripping from the venturi, so where does the excess gas come from? I inspected the plugs and they are black soot. Wire brushed them off and reinstalled, but still seem to have a misfire on the rich bank. The gas smell is heavy from the exhaust on that side as well. I am thinking the throttle shaft is worn and allowing more vacuum on that bank. Would this cause a rich condition? I don't get any response from the air mix screw on that carb either, unless I completely pull it out.

There's a stumble upon acceleration too. Both of the accelerator pumps blast a nice stream of gas when pressing the throttle. It was responding better to throttle when there was a dripping venturi?!
Thanks in advance!
motor is a '64 110 HP with dual rochester carbs and dual mufflers, 4 speed manual

[Jerry Whitt]

A vacuum leak would cause a lean mixture. A rich mixture can be caused by several items.
a. Improper fuel level
b. Wrong size jet
c. Wrong gaskets
d. damaged idle mixture screw
e. heavy float (leaks, absorbs fuel)
f. leaking needle and seat
g. choke pull off not opening choke plate
h. temp sensor not releasing pressure on choke as engine warms
i. high fuel pressure
j. problem in power enrichment needle

1. Start with fuel pressure tests. 3-4 lbs would be about right
2. Check choke for proper opening as engine warms
3. Check jet size, They vary in size from 45 thru 57. smaller number, less fuel. Both carbs should be the same. ( 49, 50, 51 most common.)

[recessbilly]

Thank you Jerry. I was in Hemet this week. Next time I'm there I need to come see those LMs.