Hi Bigted and AVB, got it sorted. It was the wax cyclinder that was no good. Put in my new one, warmed up the mower,approx 5 mins, while watching choke. Opened up perfectly. Will start up straight away again. I proceeded to have a good look at my old cyclinder with my jewelers glasses, and would you believe it, a tiny pin hole in it, which i gather had allowed some of the wax to escape and not push the piston out.
Thanking you
Paul.
