I have a Kohler command twin cylinder engine on leaf vacuum. checking for leave season, I note at full throttle , I only have 12.25 volts dc. Checked stator voltage which was 40 volts ac. Checked continuity for battery wire from regulator to battery, is ok. I replaced regulator, no change. I did note that regulator has no ground wire as I have seen in other engines. Should I run a wire from regulator mount bolt to a good ground to see if voltage increases? Thanks for any help.