Its not good to run the generator unloaded for long, you want to have at least a light load on so its not bouncing or surging off the governor. Just enough to hear the RPM drop a little. A little cube heater works fine, doesn't take much. I can turn on the AC fan and hear the RPM drop some, plus the lights and the battery charger loads it some. The main thing is good fuel if its a gasoline unit! I exercise mine at least once a month or more year round. I'm still on the original 2005 carb. Been using Marine Stabil and an occasional dose of Berry's for a long time with good results.