Thank you. Mower runs about 15 minutes then dies, then backfires really loud. It won't start up again until the next day. Thank you for your help. Wandas

Hi,
Time for a new ignition, Briggs calls them armatures. One does both sides, both plugs fire whether they are making power or not.
Peace,
Clarke

Replace the in line fuel filter, mine plugged up and did same thing, was not 100% plugged so would run, slow, choke it and go etc, Filter only about three bucks, but sounds like what mine did