While you wait for answers, we may have found some information which could help you.
Click here for Springs Stratton Motorlitres of oil needed in a countax c600h ride on lawnmower?
lawn mower won't start?
Briggs and Stratton SP470?
My Briggs & Stratton 10.5 engine will start but dies after about 15 mins?
Adding oil to mower ?
Petrol or diesel?