[GrannieAnnie]

Brian is having trouble with his Murray Sentinel ride-on mower.  He said it turns over, but doesn't fire at all.  It has petrol and oil, and he doesn't think its the spark plug, anything else come to mind anyone please?

Any ideas gratefully received!     

[shedmeister]

Possibly two things. Fuel. It may have a tankfull but if the jets on the carb are blocked it will not go. Give it a squirt of carb cleaner then try.
Second is spark. Take the plug out. Hold it tight against the head so it is earthed using a pair of insulated pliars. turn the engin over and you should see a spark as long as the plug is clean.
Also check the fuel filter. Dirt in that would stop the fuel reaching the carb