[heavy evy]

I have a 1967 chevy pickup,with a 350 v8 20,00 miles on engine. Had this problem from the day I bought the truck. just paid $700
for a Holly double pumper 4776 carburetor 650 cfm. Mechanic has left town. Carb replaced 1000 MILES AGO. At IDLE the engine is LOPING; Will stall at idle unless rpm are increased. CHANGED OUT VACUUM LINES; REAR PORTS IN CARB. ARE FLOWING FUEL AT IDLE; How can I adjust this fuel flow ? Black soot at tail pipe.
If engine rpm is increased black soot droplets are blown out. Engine rpm gauge fluctuates when truck is driven.

 

[Tech @ BG]

First lower your float level down in the rear of the carburetor. This should stop fuel flowing through your secondary boosters. If it does not you may have some dirt or debris caught up in the carburetor, or your fuel pressure may be too high. Until you get that taken care of you're not going to get this to run properly. Also double check your initial timing on the engine. If it's too low that can contribute to this situation.