1994 Barchetta 182 Throttle/Choke
 

Hello, my dad just bought the boat with a 3.0L motor. He took it out and flooded it quite nicely. His mechanic friend was trying to explain the choke on this boat, and well, my dad made me confused. We have had a couple boats but usually the choke was just by pushing the key in, or a specific small lever. Can someone explain how to properly use the choke on this boat. I need to get it out today for him, but want to better know what I'm doing to avoid what he did. Any help would be great, photos for assistance.
From what I've been told, there is a button at the bottom of the shifter, which I believe allows you to shift the yolk forward, to idle up the engine?
But then dad told me something about moving it from left to right to actually use the choke? This makes no sense.
I know that this sounds like I've never driven a boat before, but I have, haha.
Thanks in advance.