I havre a Honda HR2160 - starts but wont run?

My Honda HR 2160 usually goes like a bird. During use yesterday it stopped. Plenty of petrol in tank. I was able to start it but the engine died almost immediately. (NB plenty of oil in - and it is an older mower without the "low oil engine cut out".) This morning I cannot start it at all. I assumed a fuel blockage and have cleaned out the tank, pipes, carb etc. Still wont start. Any ideas?