Engine diagnosis?

[Nlbloch]

I would appreciate some guidance on where to start looking for my problem.

Brought the car out of winter storage with no issues. Drove car for several hours without issues.

Today, the engine started normally but stalled after just a few minutes. Tried several times with throttle in different positions, spark advance down slightly, choke open, (yes, gas line valve open!) but same problem. Eventually, engine would not catch at all -- perhaps flooded.

Where would you recommend to start looking for issues that need resolution?

Thanks in advance