Hi Simon and welcomeIt sounds like your brake,clutch switch is not working or wires came off.It is a safety switch to make sure you on on tractor before it allows deck to be engaged.It would hit the pedal linkage when you push down on pedal so it knows your on machine and ready to go.There's also a seat switch but that should prevent you from starting.There may also be a deck switch that works along with brake switch but it definitely just sounds like a switch problem not a engine problem.Look under pedal by linkage to find switch.If it is a two wire switch to test use a jumper wire to connect two wires together and try it and see if it works.Sometimes they just get bent or damaged wires.If you can't find it or need more info I will need complete modal and serial numbers to look at schematics.Best of luck to you Simon and I'm here if you have follow up questions even after rating.Take carespankyx
Ii have ordered a new switch(only a fiver) I will let you know how I go on next week
Sorry it took so long to reply but sent it away for repair! Cost me £160 to find out the carb is u.s. and because its a Tecumseh a replacement is £250 if you can find one.
Runs like a dog at the moment. There were lots of bits of plastic in the carb and now when under load it doesn't run without a little choke on. I am away in London at the mo but will send you the serial/model numbers at the weekend. The mower is only 7 years old so still got some life! It may be an engine swap though.