Stumped on old Poulan 2000 Woodsman

Hoping someone has some insight on this. Short story: replaced fuel line to carb. Took carb apart except for the bottom diaphram as it was fairly stuck to the carb. Rather than risk it and because it had worked prior I left it alone. Everything else cleaned and function tested. Upon attempting to start it fired right up and idled for about 30 seconds on full choke. Any level of open choke would kill it. The throttle wanted to reply but would kill the engine. Verified it was getting fuel. After a short time it would not even idle. I noticed on the Walbro that it only has fuel in. There is no return and there is no primer bubble. Under the plastic carb plate is a triangular metal plate that is in the closed position. Not sure what that is. Any help would be appreciated. Thanks!