if it is not an inverter type if it is at 3600rpm it WILL be on target voltage wise.
something else is up on that one.
if it sounds high it is.
a friend let something hit his in the truck and bent the throttle linkage.
ran way fast and blew mov's in everything he plugged it into.
easy fix for the generator and the damaged stuff.
once fixed and set right it ran 4 weeks without incident.
this was after ike.
the open design of this one leaves the linkage vulnerable.
it is literally a engine and alt on a tube frame/handle.
Might want to rethink that.
Knew someone with a Honda non inverter genny that kept wrecking whatever he had plugged in. Portable 600 or 650 job. Great engines in those, but.............Said it "seems to run fast". It did. I tested it at 180+ volts. Had those stupid frequency lites Honda used to use and they indicated OK. Tested about 62Hz.