John,
only yesterday I experienced the same problem with my Westwood T1012. I did have a faulty safety pull switch which is located behind the clutch pedal. It was cheap and easy to replace. The mower started first time after replacing the switch but hasn't started since. Like yours, it turns over but won't fire up. I was going to change the spark plug next but don't know what to try next if that doesn't solve the problem. Doesn't completely answer your question, I know, but hope this helps with the safety switch location. If anyone else has any ideas on a solution I would also be grateful to hear from them.
Andy
August 2009