Thanks to Victa man and Joe Brown for your replies.
I've taken off the carb and cleaned the innards, jet etc. There is some wear in one spot on the poppet valve, would this affect starting? Also would it be worth replacing the rubber diaphram in case it's not sealing properly? There is also a good fuel flow when I disconnected the fuel line and turned on the tap. As you have propbably gathered it's still not starting. I will try Mr. Brown's suggestion regarding the compression leakage. The mower is where I work part-time, so I'm not in every day and I have to work on it when I can after I've done the odd few dozen other jobs. I will let you know any progress. Thanks again.
