My trusty petrol lawnmower has cut its last lawn, the engine is smoking badly and has no power when cutting. So we need a new one, Basically its got to be a budget one but with a Briggs or mountfield engine as this previous one has served for 10 years with NO maintainence whatsoever.......any suggestions or tips on whats best to look for or just pop down to the B&Q and buy the cheapest?