The battery reads 12.4 volts and slowly climbs when running . Shouldn't I be reading 13.? when running at 5000 rpms It drops when revving, into the 11's . Checked the ac volts out of the 3 yellow wires from stator all at 50+ volts at 5000 rpms and ohm readings on prongs on rectifier regulator all read good . replaced rectifier same readings. Ground from rectifier cleaned.
does there need to be a another ground to frame besides ground to starter case?
Thanks in advance for advice.

 

Don't know how much power those old Suzuki alternators produce but you get low charge rates if the connections between battery and regulator are poor. The 700 King Quad was notorious for never producing more than 13v. Jump extra wires in, direct from battery to regulator (pos and neg) and you got over 14v charge.