prime starter assembly function?

[bank loafer]

Is the prime starter assembly used in place of a choke? I have a 2002 yamaha
t50. Its carbureted but their isn't a traditional choke, either a manual on the outboard or on the control box.

It runs fine, but is hard to get started. It feels like it just needs choked, but no visible choke available. All I see on the expanded parts diagram for fuel and intake and carb is the "prime starter assembly" No choke assembly anywhere.

Your thoughts and thank-you!

[boats.net]

Prime starter is a auto choke, if not working need to remove and clean carbs and test prime starter.

[rodbolt17]

post a pic of the carb side.
there was a change