Bike only runs for a about a minute

Bike sat around for 6+ months (Virgin Islands)
- put a new battery, started right away. Rode beautifully for like 5 minutes. Stalled.
- changed the gas, started again right away. Rode beautifully for like 5 minutes. Stalled.
- checked the air filter, looks as good as new
- took the gas tank out, scrubbed the rust out, rinsed with gas
- took the fuel pump out (replaced about 1 year ago), filter looked gunky, soaked it in electric contact cleaner, dried it
--> Same thing: fuel pump primes, starts right away, sounds great, but only idles for like 30 seconds and quits
- if I try right away, runs for only a few seconds
- if I let it sit for an hour or so, runs for about 30 seconds -- less if I rev it up.

I would greatly appreciate any suggestion!

I wouldn't trust a gas tank that has developed rust, no matter how many times you clean it. I would just get a plastic tank, change the fuel filter, and see what happens next.

You say that the engine dies after 30 seconds while it's idling; what happens if it's not idling, that is, start it up and keep the RPMs up a bit.

Increasing the RPM shortens the duration the engine runs to just a few seconds.
Could there be another issue besides the tank and fuel filter (in the pump)?
Thank you!

If it dies sooner with the RPMs higher, this means that the engine is starved for fuel, most probably an obstruction in the fuel line; this could either be in the pump itself, or the injector, but you should try to clean the entire fuel route starting with the pump and ending with the injector.

Thank you, I am ordering a replacement tank, this time in plastic.
Since my fuel pump is new (replaced last year), do you know where I can purchase just the fuel filter (I saw a video showing on to disassemble it)?
How about the injector once I get to it -- block backwards compressed air to clean it?

I don't know of a place where you could get just the fuel pump filter, but a replacement fuel pump with filter is so inexpensive that you can get it just for the filter and keep the fuel pump as a backup.

Ideally you would clean the fuel injector with a dedicated cleaner, but as a first attempt you can try taking it apart, thoroughly cleaning the screen and the injector with brake cleaner (remove all rubber O-rings before), and seeing if this fixes things.

If there are still problems, run this fuel injector diagnostic test:

Wrap-up: I replaced the tank with a plastic model and after a long fight managed to replace the fuel filter inside the fuel pump. The bike now runs perfectly -- I did not have to mess with the injector.
My 2 cents: anyone living close to the sea and not driving the bike for a long while should consider replacing the metal tank with the plastic version.

Good job getting the bike to work again, and thanks for providing closure to this issue.