I have a MEP 005a. I think I have two separate issues… It runs great but Hz is low around 40 and voltage is not stable. Sometimes the voltage is at 50 volts after start up and sometimes it is at 120 tested at outlets and lugs.my Hz gauge is bad but I am checking with a meter. the Hz will only increase with manual throttle input as the dash adjustment dial has zero effect. It will produce 61hz at WOT. When the unit does produce correct voltage(120) the Hz is still only at 40hz at normal operating rpm. Any ideas on how to trouble shoot?