Surges, smells running rich. Oil ok, filter clean. TRC meter shows 55-57 hrz, 160-170 volts, red light on. Plenty of fuel in tank. No rats nests, all linkages seem to be working freely. What to check next?
Check your hose from the crankcase breather to see if there are any cracks in the hose. Like someone else said be sure to run it at least once a month with a load. That is an important step to not miss. Also I always use Stabil in my fuel.
This unit get run at least once per month with a load? Either heat pump or a/c on. Just don't think it would be good throwing all that voltage in to the system?