Before choosing a gasoline generator you need to calculate the total power of electrical devices connected, the generator capacity should be somewhat above this value in order to provide all devices with electricity. Now you can filter the generators of power, and thus significantly narrow the field of choice.
Each gasoline generator set internal combustion engine (ice). Generators with two-stroke engine is less powerful and can't work for a long time, but they just serve, they spend little fuel and can work at any temperature. These generators are suitable, for example, to the cottagers, who arrived at your site for a few hours, and they need to warm the kettle, watch TV - no more. Petrol with a four-stroke internal combustion engine can work 10 hours, their capacity is quite high. They are suitable, for example, those involved in the construction at their summer cottage.
The longevity of the generator will depend on the quality of its motor. The cheapest generators with aluminum housing motor are very short-lived, it is wiser to buy a more expensive, but really high quality generator with a cast iron housing.
It is important to choose the power phase of the generator. Some appliances will not run from single-phase devices - welding machines, electric stoves and some others, they require a three phase generator. Ordinary household appliances and construction tools work well from a single-phase gasoline generator. Devices which need three phases, also require a synchronous generator, conventional instruments are cheaper and easier asynchronous.
If you are going to frequently move the generator, try to choose a light model, light weight is particularly relevant for generators that are purchased for Hiking. On the other hand, there is no point in chasing low weight, if the generator will be for many years to stand in the basement of the country house: on the contrary, the massive device will be more reliable and besshumno.