throttle trouble

[boundstaffpress]

I have a 283 with a 2bbl carb. manual choke.
When I come to a corner, or stop sign, I push the clutch in, and the idle stays strong for a couple seconds, then gently slows and kills the engine. It hasn't always done this. It may have been happening for the last month. I only drive 500 mi per year, so it sits more than it runs.

I can pull the choke out and make it run real fast, then it doesn't die, but I also don't have to give it any gas when I let the clutch out.

Any ideas would be appreciated