Yes, maintenance is necessary so that you can use it when you need to do so. If left abandoned until there is an emergency, the generator might have problems starting. Be sure to run the generator once a quarter to make sure it is working well. Check the oil level regularly. Keep a maintenance schedule. Many generators will strain their coils when they run to the last drop of oil. If you need to store the generator for some time, add a stabilizer to the fuel in the tank or drain the remaining fuel. Keep the generator protected from rain or moisture.