The engine is a Briggs and Stratton. It has a small Flo-Jet with four bowl screws. This tells me that the engine is likely a 80000 series/3 HP. If it is a 120 VAC 60 HZ generator which is likely because of the twist lock plug, the generator will have a output of around 1250 Watts/10 amp. This is not a lot of power but if the power is out because of storm damage, 1250 Watts is better than NO watts. Clean the fuel system, change the oil, and pull the flywheel so the points that are behind the flywheel can be cleaned. The engine will run. You might need to flash the generator to get power as sometime during long idle periods, a generator will loose it's residual magnetism.