I have tried all the advise I was given and the thing still won't start. It seems that when I pull it over by hand I get a weak spark. Taking a bit of Sue's advise I removed the pull start and used an electric drill onto the flywheel nut. This spins the engine over well, but at these higher revs I get no spark at all. I have tried isolating the cut of wires and still have no spark. So I guess something in the ignition system has died.
Mike