Reply to "600 carb issue"

Update on my carb issues.
I've replaced the fuel pump and tested it to provide 5.3 lbs at the carb. Adjusted the floats at first to just at the site holes, fired her up and pritty much the same results, will start right up then about 10 seconds falls off and won't idle unless I give it a shot of gas. I adjusted the float on the primary side a little richer and still the same thing but I started to notice black smoke from the exhaust. The choke opens rather quickly so I don't think it's an issue with the choke. Once the car warms up the idle is ok but I notice a slightly rough idle and it continues with some throttle. I adjusted the timing to 20d BTDC with no change. The Vacuum gage reads about 16hg fairly steady with little change. I'm just about ready to go buy a 670 Holley but would like to see if there is anything else I might have missed. I did check the cap and rotor and changed out the plugs prior to this and all looked real good. any other input??

Thanks for the help guys,
Steve in VA