The best advice is seek advice.
The Honda EX650 generator is pretty straight forward to service but often more specialised equipment is needed to diagnose a problem, this is were we come in.
What will my Honda EX650 generator run?
The rated output is 450 watts @ 50hz with a peak of 550 watts, there is a frequenct change over to put the generator into 60hz mode, in 60hz mode the rated power is 550 watts and peak of 650, you will know that you are in 60hz mode due to the higher engine speed but there is a problem with running some equipment at this frequency. If you are running a tape deck, record player or cd player they will run faster due to the fact that they have synchro motors.
On the 50hz setting you can run a TV, DVD player, battery charger, and a few lights all at the same time, you cannot run a hair dryer, microwave or electric kettle unless it is a low wattage kettle.