While you wait for answers, we may have found some information which could help you.
Click here for Carb Briggs StrattonHow to fix a problem with briggs&stratton hp407engine?
Briggs and Stratton SP470?
Excessive Compression?
lawn mower won't start?
Briggs and Straton Motors?
my briggs and stratton 3.5hp starts up then cuts out straight away?