I've swapped a seized Kohler CV15S with a CV16S on my LT155. The old engine had a 3 amp charging system with no voltage regulator and the new engine has 15 amp w/ a regulator. I've given it a shot, the engine runs great but I only have ~12 volts at the battery (no charging), any advice?
Were the regulators wired the same? If not have you checked your wiring? Also I'd be concerned with wire guage in that system. 15amp would require thicker guage wire without causing a fire. Maybe you blew a fuse or a fuseable link due to overload?