Idle speed

[Brianfrench65]

I've installed a Marvel Shaber carburetor. When I idle with the spark fully retarted, I get a real nice low idle. Maybe to slow??
I notice the ampmeter goes from a slight charge to a slight discharge.
I do have the generator lookalike alternator (Powermaster).
With the spark advanced 1/4 way down (for slow driving), the ampmeter stays just slightly above "0".
Should I adjust up the idle slightly, so I stay positive when idleing with the spark fully retarted?
Or am I good as is?
It does not stall out.

Thank You;