i have a walk behind craftsman mower. ive had it about 12 years. never had a problem. always first pull starts up. now out of no where it dies after running for a bit. then it wont start. let it sit for awhile and then it usually does start. ive checked spark plug and it was black so i changed it. i changed air filter and took off carb and cleaned it. still no difference. it has briggs and stratton motor.
