There is an idle adjustment screw on each carb. I think inboard just
above the throttle shaft exit.
Set this to 750 rpm (yeah right) and then set the choke fast idle screw
down below to your liking. A little choke should kick in the fast idle,
but not a high rev when it's fully choked.
Setting the choke is a bit of hit or miss.
You don't want it to chug (blub-blub-blub) when cold at a full choke
and a nice fast idle when 1/2 way pushed in.
You'll get it right for a day then take something apart and mess it all
up again like we all do ;)
Toms River, NJ