You need a frequency meter to set the engine RPM on a 60HZ A.C. Generator. You need to set it at about 62 HZ No-Load. The best and easiest to use is a Kill-A-Watt meter. It measures Voltage, Amps, Frequency, Watts and Kilowatt/Hours. You can get one from MCMelectronics(dot)com 1-800-543-4330 for $22.99 Catalog number A012E, Item Number 28-10985.