Mountfield Ride-On Mower

[Burnerman]

Some Briggs carburettors have a solenoid fuel shut off valve at the base of the carburettor bowl.....once the engine is switched off, this valve effectively shuts off any fuel passing through the main jet and naturally enough, stops the engine. These aren't that common apart from maybe the Briggs Vanguard series motors.
The majority of machines with an electric start have alternator coils underneath the flywheel and a voltage regulator / rectifier bolted nearby.
John

 

[Mr Whistler]

Battery absolutely dead is the answer. I've just had exactly same problem. Cleaned and replaced everything as in the threads above. I've been jumping the battery for the last year. New battery fitted and keeps running. Lesson learnt but its had a good service. Brm brm

 

[Burnerman]

It sounds like the new battery has enough power to spin the motor over smartly.....that’s what a magneto needs, unlike a coil ignition system, of which flywheel speed is irrelevant.
John