While you wait for answers, we may have found some information which could help you.
Click here for Westwood T1200 Removemy briggs and stratton 3.5hp starts up then cuts out straight away?
westwood t1200?
lawn mower engine hunting?
Petrol or diesel?
My Briggs & Stratton 10.5 engine will start but dies after about 15 mins?
Briggs and Stratton SP470?