Hobart Champion 10,000 Kohler eng. A/C output to high

[engineer8]

T))he A/C output is to high (374 vac) would like to know what is cause, PC board?, or other cause. Checked RPM (Ok), cleaned and checked slip rings and brushes (OK), checked all connections (good). PC board is 4 yrs old. Is there anything else it could be ??