Wants to die when warmed up

Think about the symptoms and the corrective measures.. it starts to die.. you choke it and it runs.. choke enriches the mixture... that makes it easier to fire.. that might mean weak sparks.. that is where the ignition switch comes in.. if it is dirty / has bad contacts.. it is dropping voltage.. thus weak sparks.. Also, as was mentioned.. could be a vacume on the tank.. choking gives you more manifold vacume to try to suck more fuel.. easy to diagnose by cracking cap to see if it immediatly aleviates problem. Next outside possibility may be a cracked or leaking manifold/ gasket. Sometimes the cracks open up after manifold warms up... thus you loose manifold vacume...hard to diagnose...unless you had a vacume tester hooked up to the manifold.. though I havn't seen a repro manifold that had the test port.. good luck.. try the easy stuff first.

Soundguy