While you wait for answers, we may have found some information which could help you.
Click here for Briggs Stratton Hp EnginePetrol or diesel?
lawn mower engine hunting?
My Briggs & Stratton 10.5 engine will start but dies after about 15 mins?
lawn mower won't start?
my briggs and stratton 3.5hp starts up then cuts out straight away?
westwood t1200?