The motor is a 2 zyl. 12 HP diesel engine and the genarator is brazilian with 7,5 KW capacity. Everything works fine, I can handle home lights, TV's and all smaller stuff and it works with the 60 Hz. When it comes to connect my fridge or a aircondition the voltage falls to almost 0 but the capacity should be enough to handle those things. I changed the brushes from the original carbon ones to carbon-copper and it got a little better but still doesn't generate what it should.
You need a automatic voltage regulator. Sometimes if you carry a heavy load with some generators, their voltage and frequency tend to change. Hence you need something that can regulate/keep the voltage and the frequency to normal
use stabilizer for regulating dripping of voltages, it may be useful. even if same problem happening. Check once properly load calculations. May be problem with high in rush currents.
with out any previously working loads, check individually nonworking loads.It it is working with that problem is with loading.