They are like a car, generally very reliable if looked after. Our most common problems would include flat batteries after 5 months of inactivity, dead petrol after the same, flat wheels and the odd broken belt. Solutions the this include starting your machine once every 3 weeks and let it run for a bit or put a trickle charger on during the cold winter months. Belts will only break if overloaded, be sensible for example if the grass is 6 inches tall after the winter cut it at a high setting and then go over it again at a lower setting. Even small things such as switching the blades on before dropping them into grass can prolong the life of your belts.