GZ250 Won't Start

[viking79]

Hello, I am new to this forum and have a GZ250 that suddenly won't start after winter.

Things I have done:
Drained the fuel, replaced with 1.5 gallons of fresh fuel.
Checked spark (spark is good).
Starts and stays running with starter fluid (actually MAF cleaner), dies as soon as I stop spraying.
Does not start with fuel in "pri" position (nor other positions).
Removed and cleaned out some passages in carb, no help, but didn't take it very far apart, just took the bowl off and removed the jets and blew compressed air through the passages.
If fuel set to "pri" airbox will fill with fuel and drain out bottom
Fuel drains from bottom of carb if I open the bowl screw.

Any thoughts on how to trouble shoot this? If the petcock is bad it should still run in "pri" right? It doesn't seem like it should leak fuel out the air box in this position, or is that normal? Seems like a carb or maybe fuel delivery issue.

Thanks!

Eric